
LIBRARY OF CONGRESS, 



"QfP 2>Z 

Shelf _'-.T_£k 



UNITED STATES OF AMERICA. 




4 



A COMPEND OF 

Anatomy and Physiology 



ILLUSTRATED BY THE 



NEW MODEL ANATOMICAL MANIKIN 

INCLUDING A KEY, A GLOSSARY OF MEDICAL TERMS, 
AND INCIDENTAL NOTES ON PATHOLOGY 

EDITED AND COMPILED FROM STANDARD WORKS 



*y 



M. C. TIERS 



n 1 



NEW YORK 

FOWLER & WELLS COMPANY 

775 Broadway 

1891 



Copyright, 1891, BV 

Fowler & Wells Co. 

New York. 



INTRODUCTION. 



The design and construction of The New Model Ana- 
tomical Manikin " is the result of a life-long study of the 
subjects involved, by which I have become familiar, not 
only with human anatomy and physiology as exhibited in 
the natural subject, but also as illustrated in the great 
standard works of both American and European authors. 

Being an artist by profession, and having made anatomy 
and kindred subjects specialties for many years, I have 
in this work utilized my ample resources to produce in 
compact portable form a system of illustration, at mod- 
erate cost that obviates the necessity for the numerous 
separate expensive charts that have hitherto been deemed 
necessary. 

In preparing the drawings for this work I have spent 
large portions of time in the medical college, hospital, and 
general libraries of this city, and have thus had access to 
the best works on the subject now extant. Among the 
well-known anatomists whose illustrations have contrib- 
uted to the composition of this work I name the following: 

Weisse, Cloquet, Bouveret, Caldini, Erdl, Tiedeman, 



4 INTRODUCTION. 

Langenbeck, Walter, Brechet, Soemering, Arnold, Stilling, 
Wallach, Meehel, Bock, Faessebeck, Scarpa, Asch, Peipers, 
Fisher, Oesterreicher, Camper, Hannover, Santorini, Kier- 
nan, Wagner, Lauth, Mascagni, Bougery and Jacobs, 
Hirsclifeld, Gray and Jeancon. 

The charts of which this manikin is composed have 
been so arranged that the different branches of anatomy 
and physiology may be studied, each separately from the 
others, as well as in their proper relations to each other. 
Most anatomical charts, even in the best works, are de- 
signed frequently, if not generally, to exhibit the construc- 
tion of the special organ or organs represented, rejecting 
adjacent organs not necessary to such representation. On 
this account the student often finds it necessary to learn 
the relations of organs to each other from other sources. 
It has been the purpose in this manikin to obviate as far 
as possible this difficulty. Thus the bones, muscles, the 
internal viscera, the main blood-vessels throughout the 
entire organism, and the brain and nervous system, are 
each exhibited so as to be studied separately or together, 
all drawn with anatomical accuracy; and, where it has 
seemed important, magnified appended manikins of special 
organs, such as the stomach, heart, kidney, eye, ear, and 
others, are arranged in the natural relation of their parts 
around the border. 

To aid the student in the study of the subject there 



INTRODUCTION. 5 

follows, not only a complete key to all its parts, but a gen- 
eral description of anatomy and physiology derived sub- 
stantially from the standard scientific works in use in 
American medical institutions. Of these, " Gray's " and 
" Quahr s Anatomy/' and " Dalton's " and " Flint's Physi- 
ology/' have been prominent. 

In anatomical construction I have not followed in a ser- 
vile way the charts and plates from which I have drawn 
my material, but have, rather, accommodated them to the 
descriptive anatomy at hand in the standard works which 
I have endeavored faithfully to illustrate. 

In the composition of this manual it has been the pur- 
pose not only to furnish a detailed key to the manikin, but 
also to give a general outline of physiology or the func- 
tional qualities of the various organs represented. This 
often involves reference to matters not easily illustrated 
to the eye, but of much importance in understanding the 
manikin in its suggestiveness. Most of the matters of 
this sort are condensations from the well-known medical 
authorities already mentioned. 

To obviate any difficulty that might arise from the un- 
avoidable use of medical terms, I have also furnished a 
glossary, giving full explanation of such terms employed 
in this manual, as well as of others in general use in med- 
ical works. 



INDEX 

TO THE 

C H K RTS 

OF 

THE NEW MODEL ANATOMICAL MANIKIN. 



No. I. — External Muscles of Face and Neck. 

1, Frontal portion of Occipito-Frontalis ; 2, Attolens Auris ; 
3, Attrahens Auris (Temporal fascia). 4, Occipital portion 
of Occipito frontalis ; 5, 6, Orbicularis palpebrarum ; 7, 
Levator labii superioris alsequi nasi ; 8, Zygomatic minor ; 
9, Zygomatic major ; 10, Orbicularis oris; 11, Depressor 
labii infer ioris ; 12, Masseter ; 13, Sterno-cleido mastoid ; 14 
to 15, Splenius, Levator anguli scapulae, Scaleni; 16, 17, 
Trapesius; 18, Platysma-myoides; leftside. 
No. II . — Anterior view of muscles of right side of body. 

19, Platysma-myoides ; 20, Pectoralis major ; 21, Deltoid ; 22, 
Serratus magnus ; 23, 24, External Oblique ; 25, Linea alba; 
26, Pouparts ligament ; 27, Facia lata femoris. 
No. III. — Anterior view of muscles of right arm with superficial 
veins. 
28, Biceps ; 29, 30, Internal head of triceps ; 31, Supinator 
longus ; i, Cephalic vein ; j, Basilic v.; k, Posterior ulnar v.; 
1, Anterior ulnar v.; m, Median v.; n, Eadial v. 
No. IV. —Anterior view of muscles of right hand. 

1, 2, 3, 4, Digital and Palmar veins communicating with the 
Radial and Ulnar veins in the fore arm. a, b, muscles and 
tendons of the palm. 



8 THE MODEL MANIKIN PHYSIOLOGY 

No. V.— Anterior view of muscles and superficial veins of right 
leg and foot. 
46, Adductor longus muscle ; 47, Sartorius m. 48, Adductor 
magnus m. 49, Vastus externus m. 50, Rectus femoris m. 
51, Tibialis Anticus m. 52, Extensor digitorum communis 
longus m. ; o, Long Saphenous vein ; p, Branches of same 
communicating with each other and with the deep veins 
and the short saphenous vein on the posterior side of the 
leg ; s, Branches on the dorsum of the foot arising from its 
arch and communicating with the long and short saphenous 
veins ; q, Venous arch on the dorsum connecting the long 
and short saphenous veins, and r, receiving branches from 
the toes. 

No. VI. — Anterior view of deep muscles of left side of body. 

32, Os humeri ; 33, Coracio bracialis muscle ; 34, 36, Short 
head of the Biceps muscle ; 35, Pectoralis minor m.; 37, Ex- 
ternal oblique abdominis m.; 38, Rectus Abdominis m.; 39, 
Obliquis internus m.; 40, Head of the Rectus Femoris m. ; 
a, Clavicle os ; b, Manubrium of sternum ; c, Second rib 
cartilage ; d, Third rib cartilage ; e, Fourth rib cartilage ; 
f , Sternum os ; g, Symphisis pubes ; h, Anterior superior 
spine of Ilium. 

No. VII.— Muscles of the left arm. 

41, Biceps muscle; 42, Internal head of Triceps m.; 43, 44, 
Supinator longis m. ; 45, Flexor carpi radialis m. 

No. VIII.— Deep muscles of left leg and foot. 

53, Tendonous portion of vastus externus m. ; 54, Pictinseus 
m. ; 55, Adductor longus m.; 56, Adductor magnus m.; 57, 
Vastus externus m.; 58, Ligamentum Patella. 59, 61, Ex- 
tensor digitorum communis longus m.; 60, PeronaBUS longus 
brevis ; t, Patella os ; u, Tibia os. 

No. IX. — Muscles and tendons of lef c hand. 

1, Abductor pollicis Muscle ; 2, Palmaris brevis m.; 3, Tendon- 
ous extensions of muscles of arm \ 4, Muscular fibres crossing 
each ether on the fingers. 



INDEX 9 

No. X. — Anterior view of bloodvessels of face and neck. 

1, Carotid arteries; 2, Internal jugular veins; 3, External 
jugular veins ; 4, Anterior jugular veins ; 5, Facial veins ; 
6, External maxillary arteries ; 7, Angularis Art. ; 8, Tem- 
poral vein ; 9, Middle temporal v. ; 10, Ophthalmic cerebral v.; 
11, Temporal profunda from internal maxillary artery ; a, 
Occipito frontalis m. ; b, Orbicularis palpebrarum m. ; c. 
Zygomatic minor m. ; d, Zygomatic major m. ; e, Levator labii 
superioris proprius m.; f, Masseter m.; g, Triangularis men ti 
m.; h, Quadratus mentim.; i, j, Orbicularis oris m.; k,. 
Levator menti m. ; m, Larynx and Trachse ; n, Thyroid gland. 

No. XI. — Thorax showing lungs and heart between the ribs. 

1, Sternum ; 2, Clavicle ; 3, First rib ; 4, Tenth rib ; 5, Lungs ; 
6, Heart ; 7, Liver ; 8, Stomach ; 9, Spleen. 

No. XII. — Bloodvessels of left side of]face and anterior section of 
heart and lungs. 
1, Vertical section through the heart ; 2, Right auricle ; 3, 
Right ventricle ; 4, Left auricle; 5, Left ventricle; 6, Arch 
of aorta ; 7, Left carotid artery ; 8, Left subclavian artery ; 
9, Right common carotid artery; 10, Arteria innominata; 
11, Left pulmonary artery; 12, Left pulmonary vein; 13, 
Bronchial tubes : 14, Ascending vena cava ; 15, Descending 
aorta ; 16, Descending vena cava ; 17, right vena innom- 
inata ; 18, Left vena innominata ; 19, Internal jugular 
veins ; 20, External jugular veins ; 21, Anterior jugular 
veins; 22, Right inferior thyroid v.; 23, Right external 
jugular v.; 24, Superior thyroid artery ; 25, Anterior facial 
v.; 26, External maxillary artery ; 27, Superficial temporal 
art.; 28, Temporal vein ; 29, Occipital v.; 30, 31, Branches of 
temporal vein ; a, Os frontis ; b, Orbicularis palpebrarum ; 
c, Temporal muscle ; d, Occipital m. ; e, Parotid gland ; f , 
Larynx ; g, Trachea. 

No. XIII. — Anterior view of stomach and intestines, the omentum 
having been removed. 
1, Internal coating of Stomach ; 2, Portion of pancreas and 
its duct opening into the duodenum ; 3, Section of duo- 



10 THE MODEL MANIKIN PHYSIOLOGY 

denum : 4, Upper portion of small intestines or jejunum ; 
5, Lower portion of small intestines or ileum ; 6, Termina- 
tion of the ileum where it opens into the ascending colon ; 
7, Ascending colon ; 8, Transverse colon : 9, Descending 
colon ; 10 Eectum ; 11, Bladder ; 12, Right and left iliac- 
arteries and veins ; a, Portion of psoas muscle ; b, Pyloric 
orifice of stomach ; c, Cardiac orifice opening into the 
oesophagus. 

No. XIV. — Anterior and posterior view of stomach and liver. 

1, Liver as it covers the pyloric end of the stomach ; 2, Car- 
diac end of the stomach not covered by the liver. Also 
Posterior view of 1 and 2. 

No. XV. — Lateral view of section through middle of skull, face and 
neck, showing internal structure. 
1, Internal view of skull ; 2, Bones of skull covered by scalp ; 3, 
Section of superior maxillary bone ; 4, Cervical vertebra; 5, 
Nasal passages ; 6, Opening from the eustachian tube ; 7, 
Tongue ; 8, Sublingual gland ; 9, Submaxillary gland ; 10, 
Cavity of the mouth approaching the pharynx; 11, Larynx ; 
12, Trachea; 13, Cervical plexus of nerves; 14, (Esophagus; 
15, 16, Vena innominata right and left ; 17, Thoracic duct. 

No. XVI. — Deep viscera of thorax and abdomen. 

18, Internal view of ribs cut off in front ; 19, Arch of Aorta ; 
20, Right azygos vein; 21, Left azygos vein; 22, Uniting 
with the right azygos ; 23, 24, Intercostal veins and arteries; 
25, Descending Aorta ; 26, Ascending vena cava ; 27, Eight 
and left sections of diaphragm ; 28, Section of right side of 
liver with its bloodvessels ; 29, Hepatic veins entering the 
vena cava ; 30, Portal vein and its branches, showing its 
termination m the liver; 31, Hepatic artery; 32, Splenic 
artery; 33, Splenic vein; 34, Gall bladder; 35, Vertical 
section of spleen ; 36, Pancreas ; 37, Left kidney ; 38, Ver- 
tical section of right kidney ; 39, Suprarenal capsules ; 40, 
Superior mesenteric vein; 41, Inferior mesenteric vein; 
42, Superior mesenteric artery; 43, Inferior mesenteric 
artery ; 44, Ureters ; 45, Section of left side of intestines ; 



INDEX 11 

46, Section of right side of intestines ; 47, Left renal vein ; 
48, Left renal artery; 49, Right renal artery ; 50, Right renal 
vein ; 51, Mesenteric glands and vessels ; 52, 53, Right and 
left iliac arteries ; 54, Left iliac vein ; 55, Right iliac vein ; 
56, Right internal iliac artery and vein ; 57, Right external 
iliac artery ; 58, Bladder ; 59, Psoas muscles ; 60, 61, Right 
and left femoral arteries and veins ; 62, Origin of profunda 
artery and vein ; 63, Branches of profunda artery and vein; 
64, Anterior crural nerve ; A, Outline of head of femur. 

No. XVII. — Arteries of right arm with their vena comites. 

65, Subclavian artery ; 66, Subclavian vein ; 67, Axillary vein; 
68, Axillary artery ; 69, Brachial artery and two vena 
comites ; 70, Ulnar artery and two vena comites ; 71, Radial 
artery and two vena comites ; 72, Anterior interosseous 
artery and veins ; 73, Cephalic vein ; a, Deltoid muscle. 

No. XVIII. — Arteries and deep veins of right hand. 

1, Ulnar artery ; 2, Superficial palmar arch ; 3, Digital 
branches from the deep and superficial palmar arches ; 4, 
Deep palmar arch ; a, Tendons connecting the fingers with 
muscles of the fore arm ; b, Flexor brevis, pollicis. 

No. XIX. — Arteries and deep veins of right leg and foot. 

1, Femoral artery ; 2, Location of femoral foramen where the 
artery passes behind the femur ; 3, Popliteal artery ; 4, In- 
terosseous space between the tibia and fibula, where the 
popliteal artery bifurcates and one branch comes in front 
and becomes the anterior tibial artery ; 5, Anterior tibial 
artery ; 6, Metatarsal artery and veins ; 7, Branches from the 
metatarsal to the toes with double vena comites ; 8, 
Posterior tibial artery and veins ; 9, Peroneal artery and 
veins ; 10, Profunda artery ; 11, External circumflex artery ; 
12, Femoral vein ; 13, Popliteal vein ; 14, Muscular branch 
of same ; 15, Outline of femur ; 16, Outline of tibia ; 17, 
Tarsus ; 18, Metatarsus and phalanges ; 19, Fibula ; 20, 
Branch of popliteal artery, 



12 THE MODEL MANIKIN PHYSIOLOGY 

No. XX.— Principal nerves and bloodvessels of left arm. 

74, Left subclavian artery and vein ; 75 to 76, Brachial plexus 
of nerves ; 77, Ulnar nerve ; 78, Musculo cutaneous nerve ; 
a, Deltoid muscle ; b, Biceps muscle cut off ; c, Pronator 
teres. 

No. XXI.— Principal veins of left hand. 

No. XXII. — Anterior view of nerves of left leg and foot. 

1, Anterior crural nerve ; 2, Crural branch ; 3, Middle cu- 
taneous nerve ;< 4, Internal cutaneous n.; 5, Anterior division 
of obturator n. ; 6, Anterior tibial n. ; 7, Musculo cutaneous 
n. ; 8, Branch of anterior tibial n. ; 9, Extensor digitorum 
communis longus ; Extensor longus pollicis pedis ; 10, Rec- 
tus f emoris muscle ; 11, Gastrocnemius m.; 12, Vastus in- 
ternus m. ; 13, Sartorius m. cut off ; 14, Pecteneus m. ; 15, 
Adductor longus cut off ; 16, Tibia os ; 17, Anterior annular 
ligament ; 18, 19, Muscles cut off ; 20, Internal saphenous 
nerve; 21, Femoral artery and vein ; 22, Vastus externus 
muscle ; 23, Patella. 

No. XXIII. — Inebriate's brain with enlarged bloodvessels. 

No. XXIV. — Alimentary canal with organs separated. 

1, (Esophagus ; 2, Stomach ; 3, Pyloric orifice ; 4, Duodenum 
or second stomach ; 5, Liver ; 6, Spleen ; 7, 8, Jejunum and 
ileum or small intestines ; 9, Coelic valve ; 10, Coecum ; 11, 
Vermiform appendix ; 12, Ascending colon ; 13, Transverse 
colon ; 14, Descending colon ; 15, Kectum. 

No. XXV. — Diagram of circulation of blood. 

1, Heart ; 2, Arch of aorta ; 3, Descending aorta ; 4, Ascend- 
ing aorta ; 5, Periphery in the head and upper extremities ; 
6, Periphery in the lower extremities ; 7, Ascending vena 
cava; 8, Descending vena cava; 9, Coelic axis artery — Gastric, 
hepatic, splenic ; 10, Mesenteric arteries ; 11, Renal arteries ; 
12, Renal veins ; 13, Stomach ; 14, Spleen ; 15, Intestines ; 
16, Kidneys ; 17, Liver ; 18, Portal vein and branches, includ* 
ing mesenteric, gastric and splenic veins ; 19, Lungs. 



Index 13 

No. XXVI. — Confirmed inebriate's ulcerated stomach. 

No. XXVII. — Condition of stomach after death by delirium tre- 
mens. 

No. XXVIII. — Illustration of capillary circulation. 

No. XXIX.— Blood corpuscles. 

No. XXX.— Villi of intestines. 

No. XXXI.— Salivary glands. 

1, Parotid gland ; 2, duct of same ; 3, Submaxillary gland ; 4, 
Sublingual gland ; 5, Carotid artery ; 6, External jugular 
vein ; 7, Tongue ; 8, Section of inferior maxillary bone. 

No, XXXII. — Vertical section of heart showing ventricles. 

1, Eight auricle ; 2, Eight auricular appendix ; 3, Superior 
vena cava ; 4, Inferior vena cava ; 5, Left auricle ; 6, Left 
auricular appendix ; 7, Pulmonary veins ; 8, Pulmonary 
artery ; 9, Ascending aorta ; 10, Opening of pulmonary 
artery ; 11, Tricuspid valve — right auricular ventricular ; 12, 
Bicuspid valve — left auricular ventricular ; 13, Opening of 
aorta ; 14, Internal structure of left ventricle ; 15, Internal 
structure of right ventricle. 

No. XXXIII. — Lateral section through face and throat. 

1, Nasal passages ; 2, Opening of eustachian tube ; 3, Tongue; 
4, Section of inferior maxillary bone ; 5, Section of spine ; 
6, Pharynx ; 7, Epiglottis ; 8, Interior of larynx ; 9, Hard 
palate ; 10, Mucus membrane beneath the tongue ; 11, An- 
terior portion of larynx. 

No. XXXIV.-Under side of liver. 

1, Eight lobe ; 2, Left lobe ; 3, Gall bladder ; 4, Lobulus quad- 
ratus ; 5, Lobulus spegelii ; 6, Inferior vena cava ; 7, Um- 
bilical vein ; 8, Hepatic artery ; 9, Hepatic duct; 10, Portal 
vein. 

No. XXXV. — Posterior view of small intestines with mesentery 
glands and bloodvessels and recepticulum chili. 

No. XXXVI. — External posterior muscles of leg. 

1, Glutseus maximus muscle ; 2, Glutaeus medius ; 3, Semi- 
tendinosus m. ; 4, Biceps ; 5, Vastus externus ; 6, Semi- 



ii THE MODEL MANIKIN PHYSIOLOGY 

membranosus ; 7, Internal head of gastrocnemius m. ; 8, 
External head of gastrocnemius m. ; 9, 10, Gastrocnemius 
m.; 11, Soleus m.; 12, 13, Tendo achilles. 

No. XXXVII.— Posterior view of leg with external muscles re- 
moved to show the course of main arteries. 
1, Popliteal artery with vena comites; 2, Anterior tibial 
artery and veins ; 3, Posterior tibial artery and veins ; 4, 
Peroneal artery and veins ; 5, Vastus externus m. ; 6, Semi- 
membranosus m.; 7. Termination of the femoral artery 
where it becomes the popliteal artery ; fi, 9, Heads of gas- 
trocnemius m. ; 10, Flexor digitorum longus m. ; 11, Tendo 
achilles. 

No. XXXVIII.— Lateral view of skull and anterior view of cervi- 
cal vertebra and thorax. 
1, Frontal bone ; 2, Parietal b.; 3, Temporal b.; 4, Great wing 
of sphenoid b.; 5, Maler b.; 6, Superior maxillary b. ; 7, 
Nasal b. ; 8, Inferior maxillary b. ; 9, Zygomatic arch ; 10, 
Maetus auditorius externus ; a, Occipital b. ; 11 to 17, Cer- 
vical vertebra ; 19, Section of clavicle b. ; 20 to 30, inclusive, 
ribs; 31, Manubrium — first bone of sternum ; 32, Body or 
middle bone of sternum ; 33, Ensiform process, or lower end 
of sternum. 

No. XXXIX. — Lateral view of convolutions of brain and cavity of 
mouth. ■ 

1, Frontal lobe; 2, Parietal lobe; 3, Occipital lobe; 4, Tem- 
poral lobe ; 5, Supra marginal lobe ; 6, Cerebellum ; 7, Fissure 
of Silvius; 8, Fissure of Rolando; 9, Parieto-occipital 
fissure ; 10, Ganglion of the fifth nerve ; 11, Nerves to the 
teeth from the fifth nerve ; 12, Section of inferior maxillary 
bone ; 13, Spinal column. 

No. XL. — Base of brain, with roots of cranial nerves and arteries. 

1, Olfactory bulb ; 2, Opt is thalamus ; 3 to 9, inclusive, 

Cranial nerves; A, Corpus callosum ; B, Fissure of Silvius ; 

C, Cerebellum; D, Medulla Oblongata; E, Anterior lobe of 

brain ; F, Middle lobe of brain ; G, Occipital lobe of brain, 



INDEX 15 

the right cerebellum having been removed, a, Anterior 
cerebral arteries ; b, Middle cerebral arteries ; c, Basilar 
arteries; d, Posterior cerebral art. ; e, Vertebral art. 
No. XLI. —Lateral section through middle of brain with cranial 
nerves. 
1, Fissure of Rolando ; 2, Calloso-marginal fissure ; 3, Parieto- 
occipital fissure ; 4, Corpus callosum ; 5, Cerebellum ; 6, 
Ventricle ; 7, Crus cerebri ; 8, Pons varolii ; 9, Medulla 
oblongata; 10, Eyeball; 11, Olfactory nerve; 12, Optic 
nerve ; 13, Fourth p.; 14, Fifth n.; 15, Sixth n.; 16, Seventh 
n.; 17, Eighth n.; 18, Ninth n.; 19, Tongue. 
No. XLII. — Anterior view of spinal column with spinal nerves 
proceeding from left side, and lymphatics on the right side, an- 
terior portions of the ribs being removed. 

a, Ganglia of the sympathetic nerve ; b, Lymphatic glands 
and vessels ; c, Vertebra of spinal column ; d, Posterior 
portion of ribs ; e, Transverse spinous processes ; f , Clavicle; 
g, Scapula ; 29, Termination of the spinal cord within the 
first lumbar vertebra, and roots of lumbar and sacral nerves ; 
30, Lumbar plexus nerves ; 31, Sacral plexus n. ; 32, Ingui- 
cutaneous n.; 33, Anterior crural n.; 34, Ischiadicus, or 
Great Sciatic n. ; 35, Obturator n. 

No. XLIIL— The Pelvis:— k, Sacrum. 

1, Sacral foramen; m, Obturator foramen; n, Ischium; o, Crest 
of ilium; p, Ilio-pubal-eminence; q, Sympnysis pubes; r, 
Head of femur. 
No. XLIV. — Bones and lymphatics of right arm. 

h, Humerus; i, Radius ; j, Ulna; k, Lymphatic glands. 
No. XLV.— Bones of right hand. 

A Carpus:— 1 to 8, B, Metacarpus— 9.and 13; C— 10, 11, 12, 14 
and 15, Phalanges. 
No. XL VI. — Bones and lymphatics of right leg and foot. 

b, Lymphatic glands; S, Femur; t, Patella; u, Tibia; v, Fibula; 
w, Tarsus— seven bones; x, Metatarsus — five bones; y, z, 
Phalanges; — two in the great toe and three in each of the 
others. 



1(3 THE MODEL MANIKIN PHYSIOLOGY 

No. XLVIL — Bones and nerves of left arm. 

20, Cervical plexus nerves; 21, Brachial plexus n. 22, Median 
n. 23, Ulnar n. 24, Musculo-cutaneous n. 26, superficial 
radial n. ; 27, 28, Origin of spinal n. 
No. XL VIII. — Bones and nerves of left hand. 

1, Branch of median nerve, sending branches to first three 
fingers; 2, Branch distributing to index finger and thumb; 

3, Branch of ulnar n. distributing to ring and little fingers; 
a, Bones of the carpus; b, Bones of the metacarpus; c, d, e, 
Phalanges. 

No. XLIX. — Bones and nerves of left leg and foot. 

34, Great sciatic nerve; 35, Obturator n. 36, External popliteal 
or peroneal n. 37, Peroneal profundus n. 38, Anterior 
tibial n. 39, Musculo-cutaneous n. 40, Internal peroneal 
profundus n. 41, External peroneal profundus n. 42, 
Branch of anterior tibial n. Bones, see div. XLVI. 
No. L. — Posterior view of skull, spinal column and ribs. 

1, skull; 2, seven cervical vertebra; 3, twelve dorsal vertebra; 

4, Five lumbar vertebra ; 5, The sacrum, five vertebra; 6, 
Ilium; 7, Scapula; 8, Femur; 9, Cocyx. 

No. LI. — An elaborate view of the Great Sympathetic nerve, with 
all its detailed distribution. 
1, Medulla oblongata; 2, Pneumogastric nerve; 3, Branch of 
same to lung; 4, Cardiac plexus of same; 5, Cervical plexus 
nerves; 6, Brachial plexus; 7, Semi-lunar ganglion; 8, 9, 
Lumbo-aortic plexus; 10, Hypogastric plexus; 11 — 11, Inter- 
costal nerves and bloodvessels; 12, Lumbar nerves; 13, 
Sacral plexus; a, Chain of great sympathetic ganglia: A, 
Thyroid gland; B, Aorta; C, Heart; D, Right auricle; E, 
Trachea with bronchial tubes cut off at their origin; F, 
Pneumogastric plexus following the course of the (Esopha- 
gus and distributing branches to the stomach and intes- 
tines. G, Descending Aorta ; H, Intercostal veins and 
arteries; I, Stomach; J, Pyloric end of stomach; K, Trans- 
verse colon; L, Small intestines, M, N, Rectum; O, Inferior 
Vena Cava; P, Primitive Iliac artery; R, Iliac vein; S, Lung; 



INDEX m 17 

T, section of ileum: U, Section of Symphysis pubes. For 
nerves of the head, see Div. XLI. 
No. LIL— Small section of spinal cord showing the origin of a 
spinal nerve. 
1, internal gray substance of cord ; 2, Posterior root of nerve ; 
3, anterior root of nerve ; 4, Union of the two roots in one 
sheath. 
No. LIII. — Section of inferior maxillary bone of an infant, show- 
ing undeveloped teeth. 

1, 1, First developed teeth ; 2, 2, second teeth undeveloped; 3, 
wisdom tooth. 
No. LIV. — A vein laid open, showing its valves. 
No. L V.— Arch of aorta ruptured by disease. 
No. LVI. — The Caecum and lower portion of ascending colon laid 
open. 
1, Termination of ileum; 2, Appendix vermiformis; 3, Ileo- 
caecal valve; 4, opening of appendix vermiformis. 
No. LVII. — Section of small intestines laid open, showing ulcera- 
tion. 
No. LVIII. — Posterior view of left leg, external muscles having 
been removed to show the Great Sciatic nerve and its branches, 
1, Great Sciatic nerve; 2, 2, Internal popliteal and posterior 
tibial nerves; 4, Posterior femoral cutaneous n.; 5, Mus- 
cular n. ; 6, Communicans fibularis n. ; 7, Short head ol 
the biceps muscle; 8, Long head of the biceps muscle; 9, 
Integument. 
No. LIX. — Section of head of femur, showing texture of bone. 
No. LX. — Ligaments of elbow. 
No. LXI. — Ligaments of wrist. 
No. LXII. — Ligaments of shoulder. 
No. LXIII. — Ligaments of hip. 
No. LXIV. — Ligaments of ankle. 
No. LXV. — Ligaments of knee. 

No. LXVI. — Lateral view of section through the middle of the 
foot, showing the form and relations of the bones. 



18 THE MODEL MANIKIN PHYSIOLOGY 

1, lower end of tibia; 2, Astragalus; 3, Os calcis; 4, The scaph- 

oides; 5, The Cuneiforme internum; 6, Metatarsal bone of 

great toe; 7, First phalanx of great toe; 8, second phalanx 

of great toe; 9, Tendon Achilles. 

No. LXVII.— Vertical section of bone magnified, showing texture 

and arteries. • 

No. LXVIII. — Anterior view of the eye. 

1, The pupil ; 2, The Iris ; 3, Sclerotic coating ; 4, Upper eye- 
lid; 5, Eyebrow. 
No. LXIX. — Anterior view of glands and ducts of the eye, 

1, Lachrymal gland and ducts; 2, Upper eyelid; 3, Apertures 
of ducts; 4, Canaliculi; 5, Pupil; 6, Iris; 7, Puncta Lachry- 
malia; 8, Lachrymal sack and nasal duct. 
No. LXX. — Anterior view of eye-ball, the lids being removed: — 
1, Pupil; 2, Iris; 3, Sclerotic coating with bloodvessels; 4, 
Superior rectus m.; 5, External rectus m. ; 6, Inferior rectus 
m. ; 7, Internal rectus m. 
No. LXXL— Eye-ball, with nerves and muscles as seen from 
above: — 
1, Superior rectus muscles; 2, External rectus m. 3, Superior 
oblique and internal rectus muscles; 4, 5, eye-ball; 6, Lachry- 
mal gland. 
No. LXXIL— Transverse vertical section through middle of eye, 
showing lenses, coatings and muscles: — 

1, Vitreous humor; 2, Crystalline lens ; 3, Ciliary body; 4 
Pupil; 5, Cornea; 6, Optic nerve; 7, Levator palpebrae supe- 
rior m. 8, Palpebra inferior; 9, Eetina; 10, Hyaloid mem- 
brane; 11, Sclerotic coat; Choroid membrane between 10 
and 11; 12, Tendons of rectus m. 13, 13, 13, Rectus oculi 
superior; Rectus oculi inferior and Levator palpebraB supe- 
rior muscles. 
No. LXXIIL— External ear. 
No. LXXI V.— Greatly magnified bony labyrinth of ear. 

1, Superior semi-circular canal; 2, Inferior semi-circular canal; 
3, External semi-circular canal: 4, Body of the incus; 5, Mai- 



INDEX 19 

leus; 6, Ampullae on external semi- circular canal; 5, First 
turn of cochlea; 8, The cupola; 9, Ampullae on No. 3; 10, 
Ampullae on No. 2. 

No. LXXV. — External and internal ear. 

1, The opening in the ear; 2, Msetus auditorius externus; 3, 
The tympanum; 4, Eustachian tube; 5, 6, 7, Labyrinth. 

No. LXXVL— Tongue and throat. 

1, superior surface of tongue; 2, Uvula; 3, Labium superius; 
4, Nostrils. 

No . LXXVIL— Same as LXXVL with epithelial cancer. 
No. LXXVIIL— Tongue and tonsils. 

A, Ligament and mucus membrane from root of tongue to 
epiglottis; b, Tonsils. 

No. LXXIX. — A molar tooth — lateral view. 

2, Crown; 3, 3, Fangs or roots. 

No. LXXX.— Section of molar tooth. 

1, Crown; 2, 2, Ivory; 3, Pulp in its cavity; 4, 4, Nerves, arte- 
ries and veins. 

No. LXXXI. — Section of bicuspid tooth. 

1, Ivory; 2, Enamel, worn from the summit of the crown; 3, 
Pulp in its cavity. 

No. LXXXIL— Section of skin. 

a, Epidermis or cuticle; b, Stratum corneum; c, Derma or 
true skin; d, Hair follicles and sebaceous glands; e, sweat 
♦ glands; f , f , glands. 

No. LXXXIII. — Larynx— anterior view. 

1, Corpus ossis hoidei; 2, Corno majus ossis hoidei; 3, Thyro- 
hyoideum lateral ligament; 4, Thyro-hyoideum medium 
ligament; 5, Ligaments; 6, Thyroid cartilage; 7, Pomum 
adami; 8, Crico-thyroideum medium ligament; 9, Cricoid 
cartilage; 10, Annulus cartilage of tracheae; 11, Lateral 
crico-thyroideum ligament. 

No. LXXXI V.— Vertical section of larynx, showing internal struc- 
ture:— lower figure:— 



20 THE MODEL MANIKIN PHYSIOLOGY 

1, Posterior surface of epiglottis; 2, Os hyoideum; 3, thyroid 
cartilage; 4, Cricoid cartilage; 5, Lower vocal cord; 6, Ven- 
triculus larynges; 7, Upper vocal cord. 

Upper figure: — vocal cords seen from above. 

No. LXXXV. — Lateral external view of Larynx, with its muscles. 
1, Epiglottis; 2, Thyroid cartilage; 3, Cricoid cartilage; 4, 
Trachea with rings of cartilage; 5, Arytenoid cartilage; 6, 
Hyo-epiglottic membrane; 7, Crico-thyroid muscle; 8, Poste- 
rior Crico-arytenoid muscle; 9, Lateral eric o- arytenoid 
muscle; 10, Fibres of No. 9; 11, Thyro-epiglottic muscle; 12, 
Superior thyro-arytenoid muscle; 13, Transverse thyro- 
arytenoid muscle; 14, Thyro-arytenoid muscle; 15, ary- 
epigloticus muscle. 

No. LXXXVI. — Anterior view of stomach. 

1, Cardiac orifice, opening into (Esophagus; 2, Cardiac end; 3, 
Pyloric end. 

No. LXXXVII. — Internal view of healthy stomach. 

1, Mucus membrane and rugae; 2, Pyloric orifice; 3, Duode- 
num; 4, Gall Bladder; 5, Hepatic duct; 6, Pancreatic duct; 
7, Opening to (Esophagus. 

No. LXXXVTII. — Transverse horizontal section of thorax. 

1, Heart; 2, Left lung; 3, Right lung; 4, Aorta cut off; 5, 
Main pulmonary artery; 6, Right pulmonary artery; 7, 
Left pulmonary artery; 8, Descending vena cava cut off; 
9, Descending Aorta; 10, Bronchial tubes; 11, (Esophagus; 
12, Dorsal vertebra; 13, Vena Azygos; 14, Pulmonary veins; 
15, Sternum. 

No. LXXXIX. — Anterior view of heart: — 

1, Ascending Aorta; 2, Pulmonary artery; 3, Right auricular 
appendix; 4, Left auricular appendix; 5, Right coronary 
artery; 6, Great coronary vein; 7, Apex of heart; 8, Peri- 
cardium thrown back. 

No. XC. — Diagrammatic section of heart, with parts separated: — 

1, Descending vena cava; 2, ascending vena cava; 3, Right 

auricle; 4, Right ventricle; 5, Right and left pulmonary 



INDEX 2 1 

artery; 6, Pulmonary veins; 7, Left auricle; 8, Left ven- 
tricle; 9, Ascending aorta; 10, Arch of Aorta; 11, Descending 
aorta. 

No. XCI. — Transverse horizontal section through the heart: — 

1, Tricuspid valves; 2, Bicuspid valves; 3, Semi-lunar valves 
of aorta; 4, semi-lunar valves of pulmonary artery. 

No. XCII. — Muscles and tendons of outside of foot. 

1, Annular ligament; 2, Extensor digitorum communis longus; 
3, Peronseuc tertius v. parvus; 4, Abductor digitii minimi; 
5, Extensor digitorum communis brevis ; 6, Same as 4, 
being part of it. 

No. XCIIL— External kidney:— 

1, Renal duct or ureter; 2, 3, Renal artery and vein. 

No. XCIV. — Internal structure of kidney. 

1, Cortical concretions or secreting surface; 2, Pyramids mal- 
phighi; v. coni tubulosi; 3, Papilla renalis or mammillary 
process; 4, Calyx renalis; 5, Renal pelvis; 6, Ureter; 7, 
Renal artery; 8, Renal vein. 

No. XCV. — Fatty degeneration of kidney. 

No. XCVI. — Arteries of the sole of the foot: — 

1, 1, Tendons of the flexor communis and flexor longus polli-* 
cis pedis m. 2, Arterial branch to anastomose with the pos- 
terior tibial; 3, Peroneal artery; 4, Posterior tibial artery at 
the ankle; 5, 5, External and internal plantar arteries. 

No. XC VII.— Muscles and tendons of sole of foot:— 

1, Os calcis; 2, section of fascia plantaris; 3, Abductor policis, 
muscle; 4, Abductor minimi digiti m. 5, Flexor brevis dig- 
itorum m. 6, Tendon of the flexor longus pollicis m. 7, 
Lumbricales m. 

No. XCVIII. — Muscles and tendons of inside of foot: — 

1, Internal maleolus; 2, Anterior tibial tendon; 3, Adductor 
policis pedis m. 4, Tendo extensoris pollicis pedis longi. 

No. XCIX. — Arteries and tendons of back of the hand, 



22 THE MODEL MANIKIN PHYSIOLOGY INDEX 

No. C— Closed hand— outside. 

1, Anterior annular ligament of wrist; 2, 3, 4, Muscular mass 
of thumb and palm. 

No. CI. — Arteries of back of the hand, the tendons being removed. 

No. CII. — Closed hand — inside view. 

1, Extensor carpi radialis longus; 2, Extensor primi internodii 
pollicis; 3, Extensor ossis metacarpi pollicis; 4, Extensor 
secundi internodii pollicis; 5, Extensor indicis; 6, Extensor 
carpi radialis brevis; 7, Abductor indicis; 8, Abductor poll- 
icis. 






A COMPEND OF 

ANATOMY and PHYSIOLOGY, 



HUMAN ANATOMY AND PHYSIOLOGY. 

The study of the human body naturally divides itself 
into two general departments. The first, called Anatomy, 
treats of the structure of the body and the relation of its 
• various parts to each other and to the whole; and the 
second, called Physiology, which treats of the functions 
or uses of the organs. 

For convenience of study the manikin has been so con- 
structed and arranged that the structure and functions of 
the entire body may be considered under five general di- 
visions, as follows : 

1. Bones and Ligaments. 

2. Muscles, Fascia, and Tendons. 

3. The Alimentary Canal or Digestive Tract, with the Liver 

and Pancreas. 

4. Organs of Kespiration and Circulation, including Heart, 

Lungs, Larynx, and Trachea, with the blood-vessels 
and lymphatics, and also the Kidneys and the Spleen. 



24 A COMPEND OF 

5. The Brain and Nervous system, including the construc- 
tion and functions of the organs of the special senses. 

The Soman numerals in this manual refer to the corre- 
sponding parts of the manikin, and the common figures 
and small letters that follow them, to the divisions or 
organs within the parts. Where the figures and small let- 
ters are not in immediate connection with Roman numer- 
als, the reference is to the part indicated by the Roman 
numerals next preceding. 

BONES. 

The bones constitute the framework of the body, and 
are the basis of the entire physical structure, by which, 
also, the position and motions of the body are governed. 
They are composed mostly of certain forms of lime and 
gelatin, in about the proportion of one of gelatin to two 
of lime; but these proportions are different at different 
periods of life, the gelatin being in larger proportion in 
youth and the lime in old age. The gelatin gives tough- 
ness and elasticity, and the lime hardness and strength. 
On this account the bones of children are not so easily 
broken as those of persons in old age, the elastic cartilage 
yielding more readily to accidental pressure. 

If a bone be cast into the fire the gelatin will be con- 
sumed, but the lime will resist the action of the fire and 
preserve its original form, but can be crushed to powder 
by slight pressure ; but if the bone be exposed to the ac- 
tion of certain powerful acids the lime will disappear, and 
there will be left only the gelatinous matter having the 



ANATOMY AND PHYSIOLOGY. 25 

original form of the bone, but very flexible and easily bent 
in any direction, without breaking. Bone is a dense sub- 
fibrous basis filled with minute cells and traversed in all 
directions by inosculating canals termed Haversian, which 
give passage to blood-vessels and nerves. These cells are 
irregular in form and give off numerous branching tubes, 
which, by various intercommunications, form a very deli- 
cate network. (LIX., LXVII.) 

All bones are enveloped in a fibrous membrane called 
periosteum, a Greek term meaning around the bone. 
Where this membrane extends over cartilages, it is called 
perichondrium, and where it envelops the bones of the 
skull it is termed pericranium. The internal cavities of 
bones are lined with a membrane termed medullary, and 
filled with a substance called medulla, or marrow. 

The movable joints and their ligaments are -lined with a 
membrane (synovial), which secretes a lubricating fluid 
(synovia). 

The bones of the skeleton as generally enumerated, in- 
cluding the teeth, are two hundred and forty-six, as fol- 
lows: 

8 Bones of the Cranium (XXXVIII., L.). Frontal one, 
Parietal two, Temporal two, Sphenoid one, Ethmoid 
one, and Occipital one. 

14 bones of the Face (XXXVIII.). Superior Maxillary two, 
Inferior Maxillary one, Malar two, Lachrymal two, 
Turbinated two, Nasal two, Vomer one, and Palate 
two. 

U bones of Spinal Column (XXXVIIL, XXXIX., XL., 



26 A COMPEND OF 

L.). Cervical Vertebrae seven, Dorsal Vertebrae twelve, 
and Lumbar Vertebrae, five. 

4 bones of Pelvis (XLIIL, L.). Innominata two, Sacrum 
one, Coccyx one. 

24 Eibs (XXXVIII., XLIL, L.). True Ribs fourteen, False 
Ribs six, Floating Ribs four. 

1 bone Os Hyoides (tongue bone). 

1 Sternum (breast bone) (X., XXXVIIL). 

4 bones of Shoulder (X., XXXVIIL, XLIL, L.). Clavi- 
cle (collar bone) two, Scapula (shoulder blade) two. 

6 bones of Arm (XLIV., XLVIL). Humerus two, Ulna 
two, Radius two. 

16 bones of Wrist (carpal). ) 

10 bones of Hand (metacarpal). (■ (XLV., XLVIII.) 

28 bones of Fingers (phalanges). ) 

8 bones of Legs (XLVL, XLIX). Femur (thigh) two, Pa- 
tella (knee) two, Tibia two, Fibula two. 

14 bones of Ankle (tarsal). ) 

10 bones of Foot (metatarsal). I (XLVL, XLIX.) 

28 bones of Toes (phalanges). ) 

32 Teeth (XXXVIIL, XXXIX.). Incisors eight, Canine 
four, Bicuspids eight, Molars twelve. 

8 bones Sesamoid — average. 

Bones are classified as long, short, flat, and irregular, ac- 
cording as they are fitted for motion, support, or protec- 
tion, either alone or in any combinations of these qualities. 
The long bones are found in the limbs and constitute a 
system of levers for locomotion; and, while they are rela- 
tively small in the shaft or middle portion, which is dense 



ANATOMY AND V\\ YSIOLOGY. 2J 

and compact for strength, they arc more or less expanded 
and porous at the extremities, where they unite to form 
joints or articulations, and have numerous protuberances 
for the attachment of the muscular bands, by which mo- 
tion is effected. All the bones in the upper and lower ex- 
tremities with the clavicle, except the carpal and tarsal 
bones of the wrist and ankle and the patella of the knee- 
joint, are reckoned in this class. 

The short bones are the eight carpus in the wrist and 
the seven tarsus in the ankle. In each case these bones 
articulate and are bound together by ligaments in such a 
manner as to admit of the slight motion that is incident 
to their position. 

The flat bones are to be found where protection or broad 
muscular attachments are required, as in the skull and 
the scapula or shoulder-blade. These flat bones are gen- 
erally composed of two thin layers of compact tissue in- 
closing between them a variable quantity of cancellous 
tissue. In the cranial bones these layers of compact tissue 
are familiarly known as the tables of the skull; the outer 
one is thick and tough, the inner one thinner, denser, and 
more brittle; and hence termed the vitreous table. The 
intervening cancellous tissue is called the diploe. The 
flat bones are the occipital, parietal, frontal, nasal, lachry- 
mal, vomer, scapula, ossa innominata, sternum, ribs, and 
patella. 

The irregular bones are such as cannot properly be 
called long, short, or flat. They include the vertebra of 
the spinal column, including the sacrum and coccyx; the 
temporal, sphenoid, and ethmoid, in the skull, the supe- 



28 A COMPEND OF 

rior and inferior maxillary and malar, and the inferior 
turbinated, palate, and hyoides. N 

THE SKULL. 
(XXXVIII.) 

In descriptive anatomy, the bones of the skull are di- 
vided into The Cranium and The Face. The eight bones 
of the cranium and the bones of the face, except the infe- 
rior maxillary, articulate by a sort of irregular dovetail 
work, and these joints are called sutures. It is supposed 
that one of the uses of these is to permit the growth of 
the skull, as they are frequently nearly or quite obliterated 
after the growth is complete as age advances. The coro- 
nal suture unites the frontal and parietal bones; the sagit- 
tal unites the two parietal bones, forming the longitudinal 
seam along the top of the skull; the lambdoidal connects 
the occipital and parietal bones, and the squamous unites 
a portion of the temporal bone with the parietal and sphe- 
noid. 

The spaces for the lodgment of the eyes and their ac- 
cessory muscles, vessels, nerves, and glands, are termed 
orbits. Each orbit has nine openings for the transmis- 
sion of these accessories. 

The nasal cavity is divided into three longitudinal pas- 
sages called meatuses (XV., 5). 

There are two sets of teeth, milk teeth (infant), twenty 
in number, and permanent teeth, thirty-two in number. 
(XXXVIIL, XXXIX., LIIL) 



ANATOMY AND PHYSIOLOGY. 2g 

The milk teeth consist of eight incisors, four canine, 
and eight molars. 

The permanent teeth are thirty-two, sixteen in each jaw. 
Each half of each jaw proceeding from the middle con- 
tains two incisors, one canine, two bicuspids, and three 
molars. (LXXIX., LXXX., LXXXI.) The Inferior 
Maxillary or lower jaw articulates by condyles with the 
glenoid cavities in the temporal bones and are sustained 
in position so as to allow for its necessary motion, by the 
external lateral ligaments, the capsular ligament, fibrous 
cartilages, and synovial membranes. 

The Foramen Magnum is a large oval aperture in the 
occipital bone in the base of the skull, for the passage of 
the medulla oblongata, spinal accessory nerves, and verte- 
bral arteries. 

THE SPINAL COLUMN. 
(XLII.) 

The general character of the vertebrae composing this 
column may be stated thus : Each vertebra is less than an 
inch in its vertical measurement, and has an aperture 
through which the cord passes, called the vertebral fora- 
men, and another, on each side, called the foramen for the 
vertebral artery. Each has also an osseous posterior pro- 
jection called the spinous process, and a lateral process on 
each side, for the attachment of various muscles. 

The bodies of the vertebrae are piled one upon the other, 
forming a strong pillar, for the support of the cranium 
and trunk ; the arches forming a hollow cylinder behind 



30 A COMPEND OF 

for the protection of the spinal cord. The different ver- 
tebrae are connected together by means of the articular 
processes and the intervertebral cartilages; while the 
transverse and spinous processes serve as levers for the 
attachment of muscles which move the different parts of 
the spine (c). 

The first Cervical Vertebra which articulates imme- 
diately with the skull in the vertebral foramen is called the 
atlas, and is so constructed as to form a pivotal joint with 
the second vertebra, called the axis, by which the head is 
moved in every direction. 

The twelve Dorsal Vertebrae are those to which the 
ribs are attached, and are provided with cavities for their 
attachment, called facets. The facet for the first rib is en- 
tirely in the first dorsal vertebra; from the second to the 
ninth inclusive the facets are partly in the vertebra above 
and partly in the one below the junction; and for the 
tenth, eleventh, and twelfth ribs they are each entirely in 
the corresponding vertebra. Between each articulating 
pair of vertebrae there is an orifice on each side for the 
passage of nerves throughout the entire length of the 
column. 

The five Lumbar Vertebrae form the connection be- 
tween the thorax and pelvis, and the five sacral vertebrae 
in the adult become a single bone called the Sacrum, and 
is one of the constituents of the pelvis. 

The Coccyx is the lower extremity of the Sacrum, and 
is composed of four segments of bone, thus completing the 
spinal column. The spinal canal does not pass through 
it, but terminates in the fifth sacral vertebra. 



ANATOMY AND PHYSIOLOGY. 3 1 

THE PELVIS. 

(XLIII.) 

The Pelvis incloses the lower portion of the abdomi- 
nal cavity and supports the spinal column, resting on the 
two femurs. It is composed of the two bones called os 
innominatum at the sides and front, and the sacrum and 
coccyx behind (k). Each os innominatum is described in 
three divisions: the ilium or upper part (o), the ischium 
or extreme lower part (n), and the pubes in front (q). The 
acetabulum is the cavity external to the pubes, by which, in 
conjunction with the femur or thigh bone, the hip joint is 
formed (r). The large space inclosed by the pelvis, through 
which the great sciatic nerves pass to the lower extremities, 
is called the sacral foramen (1). The openings bounded 
by the pubes above and the ischium below are the passages 
for the obturator nerves and blood-vessels, and are called 
obturator foramen (m). 

THE THOEAX. 

(XXXVIII.) 

The Thorax is the bony framework inclosing the organs 
that control respiration and the circulation of the blood. 
It is formed of the twelve dorsal vertebrae on the back, of 
the twelve ribs on each side, and of the sternum or breast 
bone and the costal cartilages in front. The ribs are at- 
tached to the vertebrae by ligaments and cartilage in such 
manner as to hold them firmly in position, while there is 



32 A COMPEND OF 

all the freedom required for their slight motions in breath- 
ing. The sternum in front is composed of three pieces, 
the upper one called the manubrium (31), to which the 
first ribs are attached by cartilage, the middle one called 
the gladiolus (32), to which five ribs, from the third 
to the seventh, on each side are attached by cartilage, and 
the lower extremity called the ensiform appendix (33). 
The second rib on each side articulates at the junction of 
the manubrium and gladiolus. The eighth, ninth, and 
tenth ribs attach themselves by cartilage with each other 
and the seventh rib. The eleventh and twelfth ribs are 
free, having no attachment excej)t to their vertebrae. The 
costal cartilages allow of the freedom of action of the ribs 
required in breathing. 

THE CLAVICLE AND SCAPULA. 

The Clavicle (XXXVIIL, 19, XLIL, f), or collar 
bone, is a long bone which articulates with the upper part 
of the sternum and extends horizontally over the first rib 
to unite with the scapula in articulation with the humerus 
to form the shoulder joint. 

The Scapula (XLIL, g, L., 7) forms the back part of 
the shoulder. It is a large, flat bone, triangular in shape, 
situated at the posterior aspect and side of the thorax, be- 
tween the first and eighth ribs, its posterior border or base 
being about an inch from and nearly parallel with the 
spinous processes of the vertebrae. 

The joint is formed 'by the articulation of the head of 
the Humerus (XLIV., h) with the glenoid cavity in the 



ANATOMY AND PHYSIOLOGY. 33 

scapula; and the external extremity of the clavicle articu- 
lates with the large and somewhat triangular process of the 
scapula, which overhangs the glenoid cavity. 

BONES OP THE ARM. 

(XLIV.) 

The Humerus (h) is the longest and largest bone of the 
arm; it presents a shaft and two extremities. The upper 
extremity or head is nearly hemispherical in form; its sur- 
face is smooth and is coated with cartilage, and articulates 
with the glenoid cavity of the scapula. The shaft is almost 
cylindrical in the upper half of its extent, but prismatic 
and flattened below. The lower extremity expands laterally 
into two processes, called the internal and external con- 
dyles, between which are the trochlea and rotula, by which 
articulation is formed with the Eadius (i) and Ulna (j) 
in the forearm to form the elbow joint. These latter are 
so arranged side by side and so connected at the elbow at 
one extremity, and with the bones of the wrist at the other, 
that every necessary motion of the hand and arm may be 
easily performed. The wisdom of this arrangement is most 
apparent. 

BONES OP THE WRIST AND HAND. 

(XLV.) 

The eight bones of the wrist are called The Carpus 
(A, 1 to 8), and are arranged in two rows; the upper row 
counting from the radial to the ulnar side are the scaphoid, 
3 



34 A COMPEND OF 

semilunar, cuneiform, and pisiform; those of the lower, 
in the same manner are the trapezium, trapezoid, os mag- 
num, and unciform. The scaphoid and semilunar articulate 
with the radius, while the other bone of the forearm — the 
ulna — is attached to the wrist joint by a small articulation 
with the radius and a simple fibro-cartilage, and does not 
articulate with any of the bones of the carpus. This ar- 
rangement is in part a provision for the revolving motion 
of the forearm. 

The first five bones of the hand articulating with the 
four lower bones of the carpus are called The Metacar- 
pus (B, 9 and 13). Articulating with the lower heads of 
these and with each other to form the thumb and fingers, 
are the two additional bones of the thumb, and the three 
additional bones of each of the four fingers comprising the 
fourteen Phalanges (0, 10, 11, 12, 14, 15). 

BONES OF THE LEG. 

(XLVI). 

The Femur or thigh bone (S) is the longest, largest, 
and strongest bone in the skeleton, and almost perfectly 
cylindrical in the greater part of its extent. In the erect 
posture it is not vertical, being separated from its fellow 
above by a considerable interval, which corresponds to the 
entire breadth of the pelvis, but inclining gradually down- 
ward and inward, so as to approach its fellow toward its 
lower part, for the purpose of bringing the knee joint near 
the line of gravity of the body. The degree of this incli- 
nation varies in different persons, and is greater in the 



ANATOMY AND PHYSIOLOGY. 35 

female than in the male, on account of the greater breadth 
of the pelvis. The femur, like other long bones, is divisi- 
ble into a shaft and two extremities. The upper extrem- 
ity presents a head, a neck, and the greater and lesser tro- 
chanters. 

The Hip Joint is a ball and socket, the head of the 
femur being spherical and moving in a cavity in the pelvis 
called acetabulum. The portion below the head is smaller, 
and is called the neck. Sometimes this portion, by reason 
of its relative weakness, is fractured, and in such case re- 
covery is very slow, and in aged persons, frequently, they 
remain permanent cripples. Below the neck the bone is 
much larger, presenting an external prominence called the 
great trochanter, and an internal one called the lesser tro-* 
chanter. 

The shaft of the femur is a cylinder of compact tissue, 
with a large medullary canal. It is of great thickness and 
density in the middle third of the shaft, where the bone 
is narrowest and the medullary canal well formed; but 
above and below this, the cylinder gradually becomes thin- 
ner, owing to a separation of the layers of the bone into 
cancelli, which project into the medullary canal and finally 
obliterate it, so that the upper and lower ends of the shaft, 
and the articular extremities, more especially, consist of 
cancellated tissue, invested by a thin compact layer. The 
lower end is larger than the upper, and is furnished with 
two condyles, with an intervening notch so formed as to 
articulate with the patella and tibia to form the knee 
joint. 

The Patella (t) is a small, flat bone covering the front 



36 A COMPEND OF 

of the knee joint, the importance of which will be under- 
stood when we treat of the muscles connected with it. 

The Tibia (u) and Fibula (v) are the two bones of 
the leg below the knee. The tibia is on the inner side, 
and is large and strong for the support of the body, while 
the fibula is very slender in proportion to its length. The 
tibia expands at its head to correspond with the condyles 
and notch of the femur with which it articulates. The 
fibula does not ascend to the condyles of the femur, but 
articulates with the tibia just below its superior enlarge- 
ment. The middle portion of the shaft of the tibia is 
relatively small, but compact; while the shaft of the fibula 
is of nearly equal thickness through its entire length. 
•These two bones are united at their lower extremities, and 
together form an articulating surface, by which they are 
attached to the astragalus of the ankle joint. The connec- 
tion of these bones at their enlarged extremities leaves 
considerable space between their shafts through which 
nerves and blood-vessels pass. 



THE TAKSTTS. 
(XLVL, w w.) 

The Tarsus consists of seven bones, viz.: the calca- 
neum or os calcis, astragalus, cuboid, scaphoid, internal, 
middle, and external cuneiform bones. 

The Calcakeum (os calcis) (LXVL, 3) is the largest 
and strongest of the tarsal bones, situated at the lower and 
back part of the foot, serving to transmit the weight of 



ANATOMY AND PHYSIOLOGY. 37 

the body to the ground, and forming a strong lever for 
the muscles of the calf. 

The Cuboid is placed on the outer side of the foot in 
front of the os calcis, and behind the fourth and fifth 
metatarsal bones. 

The Astragalus (LXVL, 2) is the largest of the tar- 
sal bones next to the os calcis. It occupies the middle 
and upper part of the tarsus, supporting the tibia above, 
articulating with the maleoli on either side, resting below 
upon the os calcis, and joined in front to the scaphoid. 

The Scaphoid (LXVL, 4) is situated at the inner side 
of the tarsus, between the astragalus behind and the three 
cuneiform bones in front. 

The Internal Cuneiform (LXVL, 5) is the largest 
of the three, and is situated at the inner side of the foot, 
between the scaphoid behind and the base of the first me-, 
tatarsal in front. 

The Middle Cuneiform, the smallest of the three, is 
situated between the other two bones of the same name, 
and corresponds to the scaphoid behind, and the second 
metatarsal in front. 

The External Cuneiform occupies the centre of the 
front row of the tarsus, between the middle cuneiform in- 
ternally, the cuboid externally, the scaphoid behind, and 
the third metatarsal in front. 

Thus it is apparent that the lower row of tarsal bones 
are in order as follows, counting from the inside outward : 
Internal Cuneiform, Middle Cuneiform, External Cunei- 
form, and Cuboid. 

The Metatarsus (x x x), consisting of the first five 



38 A COMPEND OF 

bones of the foot, articulate with the four above men- 
tioned. 

Phalanges (y, z). As with the hand, so with the foot, 
there are fourteen phalanges attached to the metatarsus 
— two in the great toe and three each in the other four 
toes. 

LIGAMENTS. 

The skeleton in the manikin exhibits the joints without 
the ligaments, but their nature and uses are illustrated 
separately. The bones at all their joints or articulations 
are bound together by these strong, tough, flexible, fibrous 
bands, which are so disposed as to bind the parts closely 
together, so as to prevent easy dislocation, and at the same 
time to permit all the natural movements required. Any 
violent and improper straining of these bands which tends 
to dislocate a joint is called a sprain, and is usually slow 
of recovery. The vertebrae of the spinal column are bound 
together by combinations of these bands, some of which 
extend over its entire length. The ribs also, by the same 
means, are adjusted, at their anterior and posterior extrem- 
ities, to the vertebrae and the sternum. At all the joints 
where there is variety of motion, these bands are variously 
crossed and lapped and interlaced with each other, as nec- 
essary to sustain the bones in their normal position. They 
are firmly attached by incorporation with the periosteum. 
The following are illustrations of their general character : 

LX., Ligaments of elbow; LXL, Ligaments of wrist; 
LXIL, Ligaments of shoulder; LXIIL, Ligaments of hip; 
LXIV., Ligaments of ankle; LXV., Ligaments of knee. 



ANATOMY AND PHYSIOLOGY. 39 

There are certain ligaments also whose function seems to 
be to prevent the displacement of certain muscles, tendons, 
and blood-vessels beneath them by muscular action. Of 
these may be noted : 

The Anterior Annular Ligament of the wrist (C, 1), 
which sustains the muscles and tendons of the hand and 
forearm in proper position; the Anterior Annular Liga- 
ment of the ankle (XXII., 17), which effects the same re- 
sult in its position; and Poupart's Ligament (II., 26), ex- 
tending from the anterior superior spine of the ilium to 
the spine of the pubes. The femoral artery and vein com- 
mence immediately behind the middle portion of this liga- 
ment. 

MUSCLES, TENDONS, FASCI.E, APONEUROSES. 

The Muscles are connected with the bones, cartilages, 
ligaments, and skin, either directly or through the inter- 
vention of fibrous structures, called tendons or aponeuro- 
ses. Where a muscle is attached to bone or cartilage, the 
fibres terminate in blunt extremities upon the periosteum 
or perichondrium, and do not come in direct relation with 
the osseous or cartilaginous tissue. Where muscles are 
connected with the skin they either lie as a flattened layer 
beneath it, or are connected with its areolar tissue by 
larger or smaller bundles of fibres, as in the muscles of 
the face. 

The muscles vary extremely in their form. In the limbs 
they are of considerable length, especially the more super- 
ficial ones, the deep ones being generally broad; they sur- 



40 A COMPEND OF 

round the bones and form an important protection to the 
various joints. In the trunk they are broad, flattened, 
and expanded, forming the parietes of the cavities which 
they inclose; hence the reason of the terms, long, broad, 
short, -etc v used in the description of a muscle. 

Tendons are white, glistening fibrous cords, varying in 
length and thickness, sometimes round, sometimes flat- 
tened, of considerable strength, and only slightly elastic. 
They are the cords by which certain muscles are attached 
to the bones. 

The Fascia are fibro-areolar or aponeurotic laminae, of 
variable thickness and strength, found in all regions of the 
body, investing the softer and more delicate organs. 

Aponeuroses are fibrous membranes of a pearly-white 
color, iridescent, glistening, and similar in structure to. the 
tendons. 

The tendons, aponeuroses, and fasciae in general are the 
appendages of the muscles, for protection^ aid, and attach- 
ment in the performance of their functions. 

The Muscles are the fleshy portions of the body, and 
are the organs which* by contraction and relaxation, pro- 
duce all its motion. They are composed of bundles of 
fibrous tissue, inclosed in cellular sheaths. 

Voluntary muscles act under the direction of the will; 
involuntary muscles act independent of the will. The 
latter control the functions of the vital organs within the 
body. In the limbs it is necessary that there be muscles 
for bending the organs in opposite directions; hence some 
are called flexors, and others extensors, on the opposite 
sides. 



ANATOMY AND PHYSIOLOGY. 41 

As the muscles and tendons constitute the bands by 
which movements of the skeleton are effected, it is import- 
ant in their study not only to refer to those parts of the 
manikin representing the muscles, but also to those repre- 
senting the skeleton. 

MUSCLES OF THE HEAD, FACE, AND NECK. 

(I.) 

The Occipito-froxtalis covers the front, top, and 
back of the head, from the eyebrows to the occiput. The 
frontal portion (1) raises the eyebrows and wrinkles the 
forehead. 

The Orbicularis Palpebrarum (5, 6), with the aid of the 
corrugator supercilii, and the tensor tarsi, which it con- 
ceals, closes the eyelids and draws the eyebrows downward 
and inward. 

Levator labii superioris almque nasi (7) raises the upper 
lip and expands the opening of the nose. 

Zygomatic major (9) and Zygomatic minor (8) pull the 
corner of the mouth upward and outward. 

Orbicularis oris (10) surrounds the mouth and closes 
and contracts the lips. 

Depressor labii inferioris (11) raises and protrudes the 
chin. 

Masseter (12), with the Temporal and Internal Pterygoid, 
closes the jaws and performs the bruising motion in 
chewing. 

The Buccinator circumscribes the cavity of the mouth 
and shortens the cavity of the pharynx in swallowing. 



42 A COMPiEND OF 

Platysma myoides (18) draws the angle of the mouth, 
depresses the lower jaw, and produces traction on the in- 
teguments of the neck. 

Sternocleido- Mastoid (13) co-operates with the above in 
bending the head forward; either one acting singly draws 
the head toward the shoulder and carries the face to the 
opposite side. It extends from the mastoid process to 
the superior extremity of the sternum. 

Trapezius (16, 17). The upper fibres draw the shoulder 
upward and backward, the middle directly backward, and 
the lower downward and backward. It is attached to 
the spinal column from the occipital bone to the 12th 
dorsal vertebra, and its fibres from this line converge to 
the acromion and the spine of the scapula. 

Levator anguli scajmlce (15) lifts the upper angle of the 
scapula and aids to carry the shoulder upward and back- 
ward. 

The Splenitis (14) of one side draws the vertebral col- 
umn back and to one side, and the two acting together 
draw the head forward. 



ANTERIOR MUSCLES ON THE RIGHT SIDE 
OF THE BODY. 

(II.) 

Platysma myoides (19) (see I., 18). 

Pectoralis major (20), with pectoralis minor, which it 
covers, draws the arms toward the chest. 

Deltoid (21) raises the arms, ^t the shoulder joint. 



ANATOMY AND PHYSIOLOGY. 43 

SerraPus Mag nus (22) is attached in front to the eight 
upper ribs, and behind is inserted into the margin of the 
posterior border of the scapula. Its action involves most 
of the motions of the shoulder and the ribs. 

External oblique (23, 24) is situated on the side and 
front of the abdomen, being the largest and most superfi- 
cial of the three flat muscles in this region. It arises by 
eight fleshy digitations from the external surface and 
lower borders of the eight inferior ribs. Some of its 
fibres pass nearly vertically downward, to be inserted into 
the anterior half of the outer lip of the crest of the ilium; 
the middle and upper fibres, directed downward and for- 
ward, terminate in tendinous fibres, which spread out into 
a broad aponeurosis. This aponeurosis, joined with that 
of the opposite muscle, along the median line (25), covers 
the whole front of the abdomen; above, it is connected 
with the lower border of the pectoralis major; below, its 
fibres are closely aggregated together, and extend ob- 
liquely across from the anterior superior spine of the ilium, 
to the spine of the os pubis and the linea ilio-pectinea. In 
the median line it interlaces with the aponeurosis of the 
opposite muscle, forming the linea alba (25), and extends 
from the ensiform cartilage (XXXVIII., 33) to the sym- 
physis pubis (VI., g)j This broad muscle moves the ribs 
and abdomen in breathing. 

Linea alba (25). A tendinous cord along the middle 
line of the abdomen where the muscles of the two sides 
meet. 

Poapartfs Ligament' (26) is a portion of the expansive 
aponeuroses of the external oblique muscle, extending from 



44 A COMPEND OF 

the anterior superior spine of the ilium to the spine of 
the os pubis. It is a broad band folded inward, and con- 
tinuous below with the fascia lata. 

* Fascia lata femoris (27) is the deep areolar tissue invest- 
ing the muscles of the thigh. It is attached above to 
Poupart's ligament and the crest of the ilium, behind to 
the margin of the sacrum and coccyx, internally to the 
pubic arch and linea ilio-pectinea, and below to all the 
prominent points around the knee joint, the condyles of 
the femur, tuberosities of the tibia, and the head of the 
fibula. 

ANTERIOR MUSCLES OF THE EIGHT ARM. 

(III.) 

Biceps (28) occupies the whole of the anterior surface 
of the arm and is attached by its short tendinous head to 
the coracoid process, and by its long head to the upper 
margin of the glenoid cavity in the scapula above, and be- 
low, by a flattened tendon inserted into the back part of 
the tuberosity of the radius. It bends the arm at the el- 
bow joint. 

Triceps (29, 30) extends the entire length of the back 
of the humerus. In its upper portion it is divided into 
three heads. Its middle or scapular head, arising by a 
flattened tendon from a rough triangular depression be- 
low the glenoid cavity, blends at its upper part with the 
capsular and glenoid ligaments. The external head arises 
from the posterior surface of the shaft of the humerus. 



ANATOMY AND PHYSIOLOGY. 4$ 

The internal head also arises from the posterior surface of 
the shaft of the humerus, and the internal border of the 
humerus and internal intermuscular septum. 

These three divisions of the muscle converge to a com- 
mon tendon, which is inserted into the back part of the 
under surface of the olecranon process. 

This is the great extensor of the forearm^ serving when 
the arm is bent to return it to its former position. 

Supinator longus (31) arises from the upper two-thirds 
of the external condyloid ridge of the humerus, and from 
the external intermuscular septum. The fibres terminate 
above the middle of the forearm in a flat tendon which is 
inserted into the styloid process of the radius. This is one 
of the extensors of the forearm. (For other muscles of 
arm see VII.) 

MUSCLES OF THE HAND. 
IV. 

Muscles and Tendons of the palm (a, b). 

IX. 

Abductor pollicis (1) arises from the ridge of os trape- 
zium and annular ligament and is inserted by a thin, flat 
tendon into the radial side of the base of the first phalanx 
of the thumb. This muscle, with the opponens pollicis 
and flexor brevis pollicis, compose the fleshy portion of 
the inside of the thumb. 

Palmaris brevis (2) arises by tendinous fasciculi from 
the annular ligament and palmar fascia; its fleshy fibres 



46 A COMPEND OF 

pass horizontally inward to be inserted into the skin oil 
the inner border of the palm of the hand. 

Flexor tendons (3), Muscular fibres (4) forming sheath 
of flexor tendon. 

Lumbricales are four small, fleshy fasciculi, accessories 
to the deep flexor muscle, and are attached to the four 
fingers. 

0. 

Anterior annular ligament of wrist (1) is a strong, 
fibrous band, which arches over the carpus, beneath which 
pass the flexor tendons of the fingers. There is also a 
ligament across the back of the wrist, which forms a 
sheath for the extensor tendons in their passage to the 
fingers, having attachments both to the ulna and the 
radius, and some of the bones of the carpus. It is called 
the posterior annular ligament. 

Palmaris Brevis (2) (see IX., 1). 

Abductor Minimi Digiti (4) arises from the pisiform 
bone, and from an expansion of the tendon of the flexor 
carpi ulnaris, and terminates in a flat tendon «.which is 
inserted into the ulnar side of the base of the first phalanx 
of the little finger. 

OIL 

Extensor carpi radialis longus (1); Extensor primi in- 
ternodii pollicis (2); Extensor ossis metacarpi pollicis (3); 
Extensor secundi internodii pollicis (4); Extensor indicis 
(5) ; Extensor carpi radialis brevis (6). The foregoing six 
muscles are for the straightening* of the iturcb and fingers. 



ANATOMY AND rilYSIOLOCV. 47 

Abductor indicia (7) and Adductor pollicis (8) are aids 
both to the extensors and flexors in certain movements. 



MUSCLES OP THE LEG. 
V. 

Adductor longus (46), Adductor magnus (48), and Ad- 
ductor brevis arise from the pubic portion of the pelvis, 
and their radiating fibres attach themselves to the inner 
side of the femur from the lesser trochanter above to the 
internal tuberosity below. The aponeurosis of the adduc- 
tor magnus is pierced close to its attachment to the femur 
in its lower portion by the foramen of the femoral vessels. 

Sartorius (47), the longest muscle in the body, is flat, 
narrow, and ribbon-like; it arises by tendinous fibres frorn 
the anterior superior spinous process of the ilium and the 
upper half of the notch below it, passes obliquely across 
the upper and anterior part of the thigh, from the outer 
to the inner side of the limb, then descends vertically, as 
far as the inner side of the knee, passing behind the inner 
condyle of the femur, and terminates in a tendon, which, 
curving obliquely forward, expands into a broad aponeu- 
rosis, inserted into the upper part of the inner surface of 
the shaft of the tibia, nearly as far forward as the crest. 
This is sometimes called the tailor muscle from its uses in 
crossing the legs. 

Quadriceps extensor includes four muscles on the front 
of the thigh. It is the great extensor muscle of the leg, 
forming a large, fleshy mass, which covers the front and 



48 A COMPEND OF 

sides of the femur, being united below into a single tendon, 
attached to the tibia, and above subdividing into separate 
portions, which have received distinct names. Of these, 
one occupying the middle of the thigh, connected above 
with the ilium, is called Rectus Femoris (50), from its 
straight course. The other divisions lie in immediate con- 
nection with the shaft of the femur, which they cover from 
the condyles to the trochanters. The portion on the outer 
side of the femur is termed the Vastus externus (49) ; that 
covering the inner side, the Vastus interims; and that 
covering the front of the femur, the Crureus. The two 
latter portions are, however, so intimately blended as to 
form but one muscle. 

The tendons of the different portions of the Quadriceps 
extensor unite at the lower part of the thigh, so as to 
form a single strong tendon, which is inserted into the up- 
per part of the patella. More properly the patella may be 
regarded as a sesamoid bone, developed in the tendon of 
the Quadriceps; and the ligamentum patellae which is 
continued from the lower part of the patella to the tuber- 
osity of the tibia, as the proper tendon of insertion of the 
muscle. 

Tibialis anticus (51) is on the outer side of the tibia, 
and arises from the outer tuberosity and upper two- 
thirds of the external surface of its shaft and adjacent 
parts. The fibres pass downward and develop into a ten- 
don which passes through the anterior annular ligament 
and is inserted into the internal cuneiform bone and base 
of the metatarsal bone of the great toe. 

Extensor digitorum communis longus (52) arises from 



ANATOMY AND PHYSIOLOGY. 49 

the outer tuberosity of the tibia and the upper three- 
fourths of the anterior surface of the shaft of the fibula 
and adjacent fascia. It terminates in three tendons which 
pass through a canal in the annular ligament with the 
peroneus tertius, run across the dorsum of the foot and 
are inserted in the second and third phalanges of the 
four lesser toes, the innermost tendon being subdivided 
into two. The Peroneus tertius is part of this muscle and 
might be described as its fifth tendon, which is inserted 
into the dorsal surface of the base of the metatarsal bone 
of the little toe on the inner side. 

VIII. 

Tendinous portion of Vastus externas (53) (see V., 49). 
Pectineus (54) has its origin in the surface of bone betw T een 
the pectineal eminence and spine of the pubes, and is at- 
tached to the crest of the pubis. The fibres pass down- 
ward and outward and backward to be inserted in a rough 
line, leading from the trochanter minor to the linea aspera. 
This muscle and the three adductors (see V., 46, 48) ad- 
duct the thigh powerfully, especially in horse exercise. 

Adductor longus (55), Adductor magnus (56), Vastus ex- 
ternus (57) (see V., 46, 48, 49). 

Ligamentum jxiteUce (58) is that portion of the com- 
mon tendon of the extensor muscles of the thigh which 
is continued from the patella to the tubercle of the tibia, 
supplying the place of an anterior ligament. It is a 
strong, flat band, about three inches in length, attached 
above to the apex of the patella and the rough depression 
4 



50 A COMPEND OF 

on its posterior surface ; below to the lower part of the 
tuberosity of the tibia; its superficial fibres being contin- 
uous across the front of the patella with those of the ten- 
don of the Quadriceps extensor. 

Extensor digitorum communis longus (59, 61) (see V., 
52). 

Peroneus longus, brevis (60). These two muscles are 
attached to the shaft of the fibula, and the fibres passing 
downward develop into tendons which pass together 
through the same groove behind the external malleolus. 
The brevis then passes through a separate sheath on the 
outer side of the os calcis, above that for the tendon of 
the longus, and is finally inserted in the dorsal surface in 
the base of the metatarsal bone of the little toe on its outer 
side. The tendon of the longus, after passing the groove, 
as above, is then reflected forward across the outer side of 
the os calcis; having reached the outer side of the cuboid 
bone, it runs in a groove on the under surface of that bone 
and crosses the sole of the foot obliquely and is inserted 
into the outer side of the base of the metatarsal bone of 
the great toe. 

XXXVI. 

Gluteus maximus (1) is a thick, fleshy mass of large 
size, of much importance in sustaining the trunk in an 
erect position. The fibres are remarkably coarse. It 
arises from the superior curved line of the ilium, and the 
portion of bone including the crest, immediately behind 
it ; from the posterior surface of the last piece of the sa- 



ANATOMY AND PHYSIOLOGY. 5 1 

crum, the side of the coccyx, and posterior surface of the 
great sacro-sciatic and posterior sacro-iliac ligaments. The 
fibres are directed obliquely downward and outward; those 
forming the upper and larger portion of the muscle (after 
converging somewhat) terminate in a thick tendinous 
lamina, which passes across the great trochanter and is in- 
serted into the fascia lata covering the outer side of the 
thigh, the lower portion of the muscle being inserted into 
the rough line leading from the great trochanter to the 
linea aspera, between the Vastus externus and Adductor 
magnus. 

Glutens meclius (2) is a broad, thick, radiated muscle, 
situated on the outer surface of the pelvis. Its posterior 
third is covered by the gluteus maximus; its anterior two- 
thirds by the fascia lata, which separates it from the in- 
tegument. It arises from the outer surface of the ilium, 
between the superior and middle curved lines, and from 
the outer lip of that portion of the crest which is between 
them; it also arises from the dense fascia (gluteal apo- 
neurosis) covering its anterior part. The fibres converge 
to a strong flattened tendon, which is inserted into the ob- 
lique line which traverses the outer surface of the great 
trochanter. 

Gluteus minimus, the smallest division of the glutei, is 
immediately beneath the two preceding. 

Semitendinosus (3) arises from the tuberosity of the 
ischium, by a tendon common to it, and the long head of 
the biceps, and from an aponeurosis which connects the ad- 
jacent surfaces of the two muscles to the extent of about 
three inches after their origin. It forms a fusiform muscle, 



r 2 A COMPEND OF 

which, passing downward and inward, terminates a little 
below the middle of the thigh in a long, round tendon 
which lies along the inner side of the popliteal space, then 
curves around the inner tuberosity of the tibia and is in- 
serted into the upper part of the inner surface of the shaft 
of that bone, nearly as far forward as its anterior border. 
This tendon lies beneath the expansion of the sartorius 
and below that of the gracilis, to which it is united. 

Semimembranosus (6) is situated at the back part and 
inner side of the thigh. It arises by a thick tendon from 
the upper and outer facet, on the back part of the tuber- 
osity of the ischium, above and to the outer side of the bi- 
ceps and semitendinosus, and is inserted into the inner 
and back part of the inner tuberosity of the tibia, beneath 
the internal lateral ligament. The tendon of this muscle, 
at its lower extremity, divides into three portions: the 
middle portion is inserted in the inner tuberosity, the in- 
ternal portion is horizontal and passes to be inserted into 
a groove along the inner side of the internal tuberosity. 
The posterior division passes upward and backward to be 
inserted into the back part of the outer condyle of the 
femur, forming the chief part of the posterior ligament of 
the knee joint. 

The tendons of the two preceding muscles, with those 
of the gracilis and sartorius, form the inner hamstring. 

The muscles of this region are supplied by the great 
sciatic nerve. 

The hamstring muscles flex the leg upon the thigh. 
When the knee is semi-flexed the biceps, in consequence 
of its oblique direction downward and outward, rotates 



ANATOMY AND PHYSIOLOGY. 53 

the leg slightly outward; and the semimembranosus, in 
consequence of its oblique direction, rotates the leg inward, 
assisting the popliteus. Taking their fixed point from 
below, these muscles serve to support the pelvis upon the 
head of the femur, and to draw the trunk directly back- 
ward in the form of an arch. 

Biceps (4) is a large muscle of considerable length, sit- 
uated on the posterior and outer aspect cf the thigh. It 
arises by two heads : one, the long head, arises from the 
lower and inner facet on the back of the tuberosity of the 
ischium, by a tendon common to it and the semitendinosus. 
The femoral or short head arises from the outer lip of 
the linea aspera, between the adductor magnus and vastus 
externus, extending from a short distance below the in- 
sertion of the gluteus maxim us, to within two inches of 
the outer condyle; it also arises from the external inter- 
muscular septum. The lower extremity develops a ten- 
don which is inserted into the outer side of the head of 
the fibula. At its insertion the tendon divides into two 
portions, which embrace the external lateral ligament of 
the knee joint, a strong prolongation being sent forward 
to the outer tuberosity of the tibia, which gives off an ex- 
pansion to the fascia of the leg. The tendon of this mus- 
cle forms the outer hamstring. 

Vastus externus (5) (see V., 49). 

Gastrocnemius (9, 10), Internal head (7), External head 
(8). This muscle forms the greater part of the calf of the 
leg. It arises by two heads which are connected to the 
condyles of the femur by two strong, flat tendons. The 
inner head, the larger, and a little the more posterior, 



54 A COMPEND OF 

arises from a depression of the upper and back part of the 
inner condyle. The outer head arises from the upper and 
back part of the external condyle, immediately above the 
origin of the popliteus. Both heads, also, arise by a few 
tendinous and fleshy fibres from the ridges which are con- 
tinued upward from the condyles to the linea aspera. Each 
tendon spreads out into an aponeurosis, which covers the 
posterior surface of that portion of the muscle to which it 
belongs; that covering the inner head being longer and 
thicker than the outer. From the anterior surface of 
these tendinous expansions muscular fibres are given off. 
The fibres in the median line which correspond to the ac- 
cessory portions of the muscle derived from the bifurca- 
tions of the linea aspera, unite at an angle upon a median 
tendinous raphe below ; the remaining fibres converge to 
the posterior surface of an aponeurosis which covers the 
front of the muscle, and this, gradually contracting, 
unites with the tendon of the soleus and forms with it the 
Tendo Achillis. 

Soleus (1) is a broad, flat muscle situated immediately 
beneath the preceding. It arises by tendinous fibres from 
the back part of the head of the fibula, and from the 
upper third of the internal surface of its shaft; from the 
oblique line of the tibia and from the middle third of its 
internal border ; some fibres also arise from a tendinous 
arch placed between the tibial and fibular origins of the 
muscle beneath which the posterior tibial vessels and 
nerve pass. The fibres pass backward to an aponeurosis 
which covers the posterior surface of the muscle, and this, 
gradually becoming thicker and narrower, joins with the 



ANATOMY AND PHYSIOLOGY. 55 

tendon of the gastrocnemius, and forms with it the Tendo 
Achillis. 

Plantaris is a small muscle between the Soleus and Gas- 
trocnemius, near their origin having a peculiarly long ten- 
don which extends to the tendo Achillis. Its characteristics 
are not uniform, as the muscle is sometimes double and 
sometimes absent altogether, and its tendon is occasionally 
lost in the internal annular ligament or in the fascia of 
the leg. 

Tendo Achillis, the common tendon of the Gastrocne- 
mius and Soleus, is the thickest and strongest tendon in 
the body. It is about six inches in length, and formed by 
the junction of the aponeurosis of the two preceding mus- 
cles. It commences about the middle of the leg, but re- 
ceives fleshy fibres on its anterior surface nearly to its 
lower end. Gradually becoming contracted below, it is 
inserted into the lower part of the posterior tuberosity of 
the os calcis, a synovial bursa being interposed between the 
tendon and the upper part of the tuberosity. The tendon 
spreads out somewhat at its lower end, so that its narrow- 
est part is usually about an inch and a half above its in- 
sertion. The tendon is covered by the fascia and the in- 
tegument, and is separated from the deep muscles and 
vessels by a considerable interval filled up with areolar 
and adipose tissue. Along its outer side, but superficial 
to it, is the external saphenous vein. 



56 A COMPEND OF 

MUSCLES AND TENDONS OF THE FOOT. 
XCIL 

Anterior annular ligament (1) consists of a superior or 
vertical portion, which binds down the extensor tendons 
as they descend on the front of the tibia and fibula, and 
an inferior or horizontal portion, which retains them in 
connection with the tarsus, the two portions being con- 
nected by a thin intervening layer of fascia. The vertical 
portion is attached externally to the lower end of the 
fibula, internally to the tibia, and above is continuous with 
the fascia of the leg; it contains two separate sheaths, one 
internally, for the tendon of the tibialis anticus, one ex- 
ternally, for the tendons of the Extensor longus digitorum 
and Peroneus tertius; the tendon of the Extensor proprius 
pollicis and the anterior tibial vessels and nerve pass be- 
neath it, but without any distinct sheath. The horizontal 
portion is attached externally to the upper surface of the 
os calcis, in front of the depression for the interosseous 
ligament, and internally to the inner malleolus and plantar 
fascia. It contains three sheaths; the most internal for the 
tendon of the Tibialis Anticus, the next in order for the 
tendon of the Extensor proprius pollicis, and the most ex- 
ternal for the Extensor longus digitorum and Peroneus 
tertius : the anterior tibial vessels and nerve lie altogether 
beneath it. These sheaths are lined by separate synovial 
membranes. (See VHP) 

Internal Annular ligament is a strong fibrous band which 
extends from the inner malleolus above to the internal 



ANATO.MY AM) PHYSIOLOGY 57 

margin of the os calcis below, converting a series of bony 
grooves in this situation into osseo-fibrous canals, for the 
passage of the tendons of the Flexor muscles and vessels 
into the sole of the foot. 

External Annular ligament extends from the extremity 
of the outer malleolus to the outer surface of the os calcis; 
it binds down the tendons of the Peronei muscles in their 
passage beneath the outer angle. The two tendons are 
inclosed in one synovial sac. 

Extensor digitorum communis longus (2) (see V., 52). 

Peroncus tertius (3) (see V., 52). 

Abductor digit i minimi (4) lies along the outer border 
of the foot. It rises by a very broad origin from the outer 
tubercle of the os calcis, from the under surface of the os 
calcis in front of the tubercle, from the plantar fascia, and 
the intermuscular septum between it and the Flexor brevis 
digitorum. Its tendon, after gliding over a smooth facet 
on the under surface of the base of the fifth metatarsal 
bone, is inserted with the short Flexor of the little toe 
into the outer side of the base of the first phalanx of the 
little toe. It is supplied by the external plantar nerve. 

Extensor digitorum communis brevis (5) is a broad, thin 
muscle, which arises from the outer side of the os calcis, in 
front of the groove for the Peroneus brevis; from the ex- 
ternal calcanei-astragaloid ligament, and from the hori- 
zontal portion of the anterior annular ligament. It passes 
obliquely across the dorsum of the foot and terminates in 
four tendons. The innermost, which is the largest, is in- 
serted into the first phalanx of the great toe crossing the 
dorsalis pedis artery; the other three into the outer sides 



58 A COMPEND OF 

of the long extensor tendons of the second, third, and 
fourth toes. 

XCVIIL 

Internal malleolus (1), a rough prominence on the inner 
side of the lower extremity of the tibia, for the attachment 
of the annular ligament. 

Anterior tibial tendon (2) (see V v 51). 

Adductor pollicis pedis (3) is a large, thick fleshy mass, 
passing obliquely across the foot, and occupying the hollow 
space between the four outer metatarsal bones. It arises 
from the tarsal extremities of the second, third, and fourth 
metatarsal bones, and from the sheath of the tendon of 
the Peroneus longus, and is inserted, together with the 
outer portion of the flexor brevis pollicis, into the outer 
side of the base of the first phalanx of the great toe. 

Tendo extensoris j^ollicis pedis longi (4). Extensor ten- 
dons of the toes. 

XCVII. 

Os Calcis (1) (see XLYL, LXVL). 

Fascia Plantaris (2), the densest of all the fibrous mem- 
branes, is divided into a central and two lateral portions. 
The central portion is narrow behind and attached to the 
inner tubercle of the os calcis, and becoming broader and 
thinner in front, divides opposite the middle of the meta- 
tarsal bones into five processes, one for each of the toes. 
Each of these processes divides into two slips which embrace 
the sides of the flexor tendons of the toes, and are inserted 



ANATOMY AND PHYSIOLOGY. 59 

in the sides of the metatarsal bones and into the trans- 
verse metatarsal ligament, thus forming a series of arches, 
through which the tendons c f the short and long flexors 
pass to the toes. The lateral portions of the fascia are 
thinner than the central piece, and cover the sides of the 
foot. 

Abductor pollicis (3) lies along the inner border of the 
foot. It arises from the inner tubercle on the outer sur- 
face of the os calcis; from the internal annular ligament; 
from the plantar fascia; and from the intermuscular sep- 
tum between it and the Flexor brevis digitorum. The 
fibres terminate in a tendon which is inserted together 
with the innermost tendon of the Flexor brevis pollicis, 
into the inner side of the base of the first phalanx of the 
great toe. 

Abductor minimi digiti (4) (see XCIL, 4). 

Flexor brevis digitorum (5) lies in the middle of the 
sole of the foot, immediately beneath the plantar fascia, 
with which it is firmly united. It arises by a narrow ten- 
dinous process from the inner tubercle of the os calcis, 
from the central part of the plantar fascia, and from the 
intermuscular septa between it and the adjacent muscles. 
It passes forward and divides into four tendons. Opposite 
the middle of the first phalanges each tendon presents a 
longitudinal slit, to allow the passage of the corresponding 
tendon of the Flexor longus digitorum; the two portions 
form a groove for the reception of that tendon. The ten- 
don of the short flexor then reunites and immediately di- 
vides a second time into two processes, which are inserted 
into the sides of the second phalanges. The mode of di- 



60 A COMPEND OF 

vision of the tendons of the Flexor brevis digitorum and 
their insertion into the phalanges is analogous to the 
Flexor sublimus in the hand. It is supplied by the inter- 
nal plantar nerve. 

Tendon of the flexor longus pollicis (6). This is one of 
the deep muscles of the back part of the leg. Its tendon 
passes through a groove on the posterior surface of the 
tibia, external to that for the Tibialis posticus and Flexor 
longus digitorum; it then passes through another groove 
on the posterior extremity of the astragalus, and along a 
third groove beneath the lesser process of the os calcis, 
into the sole of the foot, where it runs forward between 
the two heads of the Flexor brevis pollicis and is inserted 
into the base of the last phalanx of the great toe. 

Lumbricales (7) are four small muscles accessory to the 
tendons of the Flexor longus digitorum. They arise from 
the tendons of the long flexor as far back as their angle of 
division, each arising from two tendons, except the inter- 
nal one. Each muscle terminates in a tendon which passes 
forward on the inner side of each of the lesser toes, and is 
inserted into the expansion of the long extensor and base 
of the first phalanx of the corresponding toe. 

THE SKIN AND ITS APPENDAGES. 
LXXXII. 

The skin is the principal seat of the sense of touch, and 
may be regarded as a covering for the protection of the 
deeper tissues. It is also an important excretory and ab- 
sorbing organ ; on which account it is indispensable to the 



ANATOMY AND PHYSIOLOGY. 6 1 

life and health of the body. It consists of two layers, the 
derma, or cutis vera (true skin) (c) and the epidermis, or 
cuticle (a). On the surface of the former layer are the 
sensitive papillae; and within or imbedded beneath it are 
the sweat glands (e), hair follicles (d), and sebaceous glands. 

The derma, or true skin, is tough, flexible, and highly 
elastic, in order to defend the internal parts from violence. 
It consists of fibro-areolar tissue, intermixed with numer- 
ous blood-vessels, lymphatics, and nerves. From the dif- 
ferences in the structure of the cutis at different parts, 
it is usual to describe it as consisting of two layers : the 
deeper layer, or corium, and the superficial or papillary 
layer. 

The corium consists of strong interlacing fibrous bands, 
composed chiefly of the white variety of fibrous tissue, but 
containing also some fibres of the yellow elastic tissue, 
which vary in amount in different parts. 

The corium varies in thickness. Thus it is thicker in 
the regions exposed to pressure, as the palm of the hand 
and the sole of the foot; thicker, also, on all portions most 
exposed, and thinner on less exposed portions. In .the 
eyelids it is exceedingly thin and delicate. 

The areola are occupied by adipose tissue, hair follicles, 
and the sudoriferous and sebaceous glands. They are the 
channels by which the vessels and nerves are distributed 
to the more superficial strata of the corium and to the 
papillary layer. 

The papillary layer is situated upon the free surface of 
the corium. It consists of numerous small, highly-sensi- 
tive, and vascular eminences, the papillae, which rise per- 



62 A COMPEND OF 

pendicularly from its surface and form the essential ele- 
ment of the organ of touch. The papillse are conical-shaped 
eminences, having a round or blunted extremity, occasion- 
ally divided into two or more parts, and connected by their 
base with the free surface of the corium. 

The epidermis, or cuticle (scarf-skin), is an epithelial 
structure accurately moulded on the papillary layer of the 
derma. It forms a defensive covering to the surface of 
the true skin, and limits the evaporation of watery vapor 
from its free surface. It varies in thickness in different 
parts of the body as exposure and pressure are incidental 
to them. 

The black color of the skin in the negro and the tawny 
color among some of the white races is due to the pres- 
ence of pigment in the cells of the cuticle. This pig- 
ment is more especially distinct in the cells of the deeper 
layer, or rete mucosum, and is similar to that found in the 
choroid. As the cells approach the surface and desiccate, 
the color becomes partially lost. 

The arteries which supply the skin divide into numerous 
branches in the subcutaneous tissue; they then pass through 
the areolae of the corium and divide into a dense capil- 
lary plexus, which supplies the sudoriferous and sebaceous 
glands and the hair follicles, terminating in the superficial 
layers of the corium, by forming a capillary network, from 
which numerous fine branches ascend to the papillae. 

The lymphatic vessels are arranged in a minute plexiform 

network in the superficial layers of the corium, where they 

become interwoven with the capillary and nervous plexuses. 

• The nerves which supply the skin ascend with the ves- 



ANATOMY AND PHYSIOLOGY. 63 

sels through the areolae of the deep layers of the corium 
to the more superficial layers, where they form a minute 
plexiform mesh. From this plexus the primitive nerve 
fibres pass to be distributed to the papillae. The nerves 
are most numerous in those parts which manifest the 
greatest sensibility. 

The appendages of the skin are the nails, the hairs, the 
sudoriferous and sebaceous glands and their ducts. The 
nails and hairs are peculiar modifications of the epider- 
mis, consisting essentially of the same cellular structure as 
that membrane. 

The skin is a vital organ, by which is meant that its func- 
tions are indispensable to life and health. The insensible 
perspiration must not be interrupted or death will speedily 
ensue, as thus the injurious elements that should be ex- 
pelled from the body are retained in it to poison the blood 
and thus overtax the vital organs within the body. 

THE ALIMENTARY CANAL. 

i-he human body is supported by elements derived from 
the air we breathe and from the food we eat. . The animal 
and vegetable substances of which the food is composed 
contain elements not nutritious, and these need to be sep- 
arated by chemical action. The nutritious qualities are 
thus made available by a process called digestion. 

The Digestive tract or alimentary canal consists of the 
mouth, pharynx, oesophagus, stomach; the duodenum, je- 
junum, and ileum, together forming the small intestine; 
and the colon — ascending, transverse, and descending— 



64 A COMPEND OF 

and the rectum (see XIII., XV., XXIV. in manikin and 
its index). 

The various substances proper for food containing the 
nutritious elements necessary for the support of the body 
are both solid and fluid. The fluids are taken into the 
mouth and pass immediately through the pharynx and 
oesophagus to the stomach; but the solids are retained in 
the mouth, to be prepared for the proper change they are 
to undergo when they pass into the stomach. This prep- 
aration is accomplished by the simultaneous grinding mo- 
tions of the teeth and the action of the tongue and inter- 
nal muscles of the mouth, while the necessary discharge of 
the salivary glands supplies the needed moisture to reduce 
the mass to the consistency necessary to pass it to the 
stomach. These glands are six in number — three on each 
side — two in the front portion of the mouth under the 
tongue, called the sublingual glands; two below the jaw in 
the anterior part of the submaxillary triangle of the neck, 
called the submaxillary glands; and two near the ear, be- 
ing larger than the others, lying on the side of the face 
immediately below and in front of the external ear, called 
the parotid glands. 

The duct of the submaxillary, called Wharton's duct, 
and the numerous ducts of the sublingual open in close 
proximity to each other under the tongue; but the orifice 
of the duct of the parotid, called Steno's duct, opens upon 
the inner surface of the cheek opposite the second molar 
tooth of the upper jaw (XXXI., 1, 3, 4, manikin and its 
index). 



ANATOMY AM) PHYSIOLOGY. 65 



IN THE MOUTH. 

The hard palate is bounded in front and at the sides by 
the alveolar arches and gums; behind it is continuous with 
the soft palate. It is covered by a dense structure formed 
by the periosteum and mucous membrane of the mouth, 
which are intimately adherent together. 

The soft palate is a movable fold, suspended from the 
posterior border of the hard palate and forming an incom- 
plete septum between the mouth and pharynx. Its upper 
border is attached to the posterior margin of the hard 
palate, and its sides are blended with the pharynx. Its 
lower border is free. Hanging from the middle of its 
lower border is a small conical-shaped pendulous process 
called the uvula. 

The space left between the arches of the palate on the 
two sides is called the isthmus of the fauces. It is bounded 
above by the free margin of the palate; below by the 
tongue and on each side by the pillars of the soft palate 
and tonsils. 

The tonsils are tw T o glandular organs situated one on 
each side of the fauces, between the anterior and poste- 
rior pillars of the soft palate. They are of a rounded form 
and vary considerably in size in different individuals 
(LXXVL, XXVIL, XXVIII.). 

The Pharynx (XXXIII., 6) is that part of the alimen- 
tary canal which is placed behind the nose, mouth, and 
larynx. It is a musculo-membranous sac somewhat coni- 
5 



66 A COMPEND OF 

cal in form, with the base upward and the apex downward, 
extending from the under surface of the skull to the cri- 
coid cartilage in front, and the fifth cervical vertebra be- 
hind. It has seven openings communicating with it; the 
two nares, the two Eustachian tubes, the mouth, larynx, 
and oesophagus. 

The posterior nares are the two large apertures situated 
at the upper part of the anterior wall of the pharynx. 
The oesophageal opening is the lower contracted portion 
of the pharynx. 

The oesophagus is a membranous canal, about nine 
inches in length, extending from the pharynx to the stom- 
ach (XV., 14). In the neck it is behind the trachea, the 
thyroid gland, and thoracic duct; behind, it rests upon 
the vertebral column and Longus colli muscle; the caro- 
tid arteries are on each side of it. In the thorax it passes- 
across the transverse part of the aortic arch, and descends 
along the right side of the aorta, nearly to the diaphragm, 
where it passes in front of the artery previous to entering 
the abdomen. 

The Diapliragm is a thin musculo-fibrous septum, placed 
obliquely at the junction of the upper with the middle 
third of the trunk, and separating the thorax from the 
abdomen, forming the floor of the former cavity and the 
roof of the latter. It arises from the whole of the inter- 
nal circumference of the thorax, being attached, in front, 
by fleshy fibres, to the ensiform cartilage; on either side, 
to the inner surface of the cartilages and bony portions of 
the six or seven inferior ribs, interdigitating with the trans- 
versalis; and behind, to two aponeurotic arches, named 



ANATOMY AND PHYSIOLOGY. 6j 

the ligamentum arcuatum externum and internum, and to 
the lumbar vertebrae. 

The action of the diaphragm modifies considerably the 
size of the chest and the position of the thoracic and ab- 
dominal viscera. During a forced inspiration, the cavity 
of the thorax is enlarged in the vertical direction from two 
to three inches. The abdominal viscera are also pushed 
down (the liver to the extent of nearly three inches), so 
that these organs are no longer protected by the ribs. 
During expiration, when the diaphragm is passive, it is 
pushed up by the action of the abdominal muscles; the 
cavity of the abdomen (with the organs contained in it) 
encroaches upon the chest, by which the lungs and heart 
are compressed upward, and the vertical diameter of the 
thoracic cavity diminished. The diaphragm is passive 
when raised or lowered by the abdominal organs inde- 
pendently of respiration, in proportion as they are large 
or small, full or empty; hence the oppression felt in the 
chest after a full meal, or from flatulent distention of the 
stomach and intestines. In all expulsive acts the diaphragm 
is called into action, to give additional power to each ex- 
pulsive effort, as before sneezing, coughing, laughing, 
crying, etc. (XVI., 27, 27). 

Physiologists have experimented much to ascertain 
whether the food or any of its ingredients pass through 
any chemical change by contact with the saliva, but it is 
quite well established that the saliva is only necessary to 
soften the solids and prepare them for passage to the 
stomach. 

The general sensibility of the tongue enables this organ 



68 A COMPEND OF 

to appreciate the physical condition of the food and its 
readiness for deglutition. At the same time its muscular 
apparatus provides for its movement in every direction. 
When the alimentary material is finally reduced, by the 
saliva and mastication, to a pasty and homogeneous con- 
dition, the softened mass is collected from every j3art of 
the mouth by the movements of the tongue, brought to- 
gether upon its upper surface, and pressed backward 
through fauces into the pharynx and oesophagus. Here it 
passes beyond the control of the will. It is then grasped 
by the muscular fibres of the oesophagus, and by a contin- 
ouus and rapid peristaltic action is carried downward into 
the stomach. 

The alimentary canal is about six times the length of 
the body, and as the food passes through it, it is acted 
upon by fluids from the mucous membrane of the canal, 
and by those from certain accessory glands. These act 
upon it in such a way as to separate the nutritious from 
the innutritious portions, the former to be mingled with 
the blood, and the latter to be expelled from the body. 
Throughout this passage it is lined by a mucous mem- 
brane and a muscular coat. The muscular coat, by its 
alternate contractions and relaxations, carries the food 
downward. Its fibres differ in its different portions, to 
be accommodated to the various movements necessary as 
the work of digestion and assimilation proceeds. 



ANATOMY AND PHYSIOLOGY. 69 

THE ABDOMEN. 
XVI. 

The Abdomen is the largest cavity in the body, and is 
separated, below, from the pelvic cavity by the brim of the 
pelvis. It is bounded in front and at the sides by the 
lower ribs, the Transversalis muscle, and the venter ilii; 
behind, by the vertebral column and the Psoas and Quad- 
ratus lumborum muscles; above, by the diaphragm; be- 
low, by the brim of the pelvis. 

The abdomen contains the greater part of the alimen- 
tary canal, some of the accessory organs to digestion, viz., 
the liver, pancreas, and spleen, and the kidneys and supra- 
renal capsules. Most of these structures, as well as the 
wall of the cavity in which they are contained, are cov- 
ered by an extensive and complicated serous membrane, 
the peritoneum. 

The apertures found in the walls of the abdomen for the 
transmission of structures to or from it are the umbilicus, 
the caval op)ening in the diaphragm for the transmission 
of the inferior vena cava; the aortic opening for the pas- 
sage of the aorta, vena azygos, and thoracic duct; and the 
oesophageal opiening for the oesophagus and pneumogastric 
nerves. Below there are two apertures on each side : one 
for the passage of the femoral vessels and the other for 
the passage of cords and ligaments. 

The stomach is an expansion of the canal, from nine to 
twelve inches long in its transverse measurement, and 



JO A COMPEND OF 

about four inches vertically. It is located in the upper 
left-hand side of the abdominal cavity, behind and below 
the lower ribs, immediately under the heart and liver. Its 
mucous membrane is thick, smooth, soft, and velvety; 
and, in the adult, is generally of a pale straw color. When 
at rest its surface is thrown into numerous plaits or rugae, 
which have a general longitudinal direction. These en- 
tirely disappear when the stomach is distended (XIII., 1) 
(LXXXVL, LXXXVII.). 

As soon as the food enters the stomach from the oesoph- 
agus there exudes from this mucous membrane a pow- 
erful solvent called the gastric juice, whose qualities are 
such that, while it performs its proper chemical work on 
the contents of the stomach, it has no effect whatever on 
the living tissues of the stomach itself, although it will act 
on these tissues after death. 

Improper food, irregular diet, gluttony, and the exces- 
sive use of alcoholic beverages tend to interrupt the func- 
tions of this organ by neutralizing the gastric juice or de- 
stroying the mucous membrane, so that the preparation of 
the mass for subsequent action in the intestines is not 
properly effected, and thus healthy nutrition is retarded 
(XXVI., XXVII.). Indeed, the entire alimentary canal 
and its accessory organs are more or less retarded in their 
functions and tend to organic disintegration by these die- 
tary irregularities, so that the complicated functions are 
disturbed ; and either abnormal enlargement of the organ 
or the opposite tendency to become shrivelled ensues, and 
inflammatory and ulcerous conditions are generated in the 
intestines and acute and malignant diseases result. 



ANATOMY AND PHYSIOLOGY. 71 

As soon as the food enters the stomach and the gastric 
juice has been added, the muscular coat begins a kneading 
or stirring motion, which continues until the entire mass 
has been affected. 

The opening through which the contents of the stom- 
ach pass out is at its right extremity and is called the pylo- 
rus. When the food has been properly changed by the 
action of the gastric juice, it is called chyme, and passes 
out through this orifice, which is guarded by a valve, into 
the duodenum, or second stomach (XIII., 3). Here it re- 
ceives the bile from the liver and the pancreatic juice from 
the pancreas. 

The Pancreas is a gland somewhat like the salivary glands, 
and its fluid closely resembles saliva in its general charac- 
ter. It extends across the upper part of the abdominal 
cavity behind the stomach, is from six to eight inches long 
and one and a half inches wide, and somewhat in the form 
of a dog's tongue. Its right extremity is in contact with 
the duodenum, and its left reaches to the spleen. On the 
posterior side is a lobular fold of the gland, which is some- 
times separated from it and is termed the lesser pancreas 
(XIII., 2; XVI., 30). 

Interposed between the pancreas and the first lumbar 
vertebra are the superior mesenteric artery and vein, the 
commencement of the portal vein, the vena cava, the aorta, 
the upper portion of the left kidney and its capsule, and 
the corresponding renal vessels (see manikin and index, 
XVI.). Through the entire length of the gland runs the 
vessel or duct which collects and conveys its fluid to the 
duodenum. This duct has various branches ramifying 



J2 A COMPEND OF 

through the substance of the gland; it also receives a 
branch from the lesser pancreas behind it. The opening 
of the pancreatic duct is usually in conjunction with the 
common duct from the liver, but sometimes they enter at 
different points. 

The Liver is a glandular organ of large size, intended 
mainly for the secretion of the bile, but effecting other im- 
portant changes in certain constituents of the blood in its 
passage through the gland. It is the largest gland in the 
bod}^ weighing from three to four pounds. It measures 
in its transverse diameter from ten to twelve inches ; from 
six to seven in its antero-posterior ; and is about three inches 
thick at the back part of the right lobe, which is the thick- 
est part (XIV., 1; XVL, 28; XXXIV.). 

Its upper surface is convex, directed upward and forward, 
smooth, covered by peritoneum. It is in relation with the 
under surface of the diaphragm; and below, to a small ex- 
tent, with the abdominal parietes. The surface is divided 
into two unequal lobes, the right and left, by a fold of peri- 
toneum, the sus2Jensory or broad ligament. 

Its under surface is concave, directed downward and back- 
ward, and in relation with the stomach and duodenum, the 
hepatic flexure of the colon, and the right kidney and 
suprarenal capsule. The surface is divided by a longitu- 
dinal fissure into a right and left lobe. 

The posterior border is rounded and broad, and connected 
to the diaphragm by the coronary ligament; it is in relation 
with the aorta, the vena cava> and the crura of the dia- 
phragm. 

The anterior border is thin and sharp,, and marked^ op- 



ANATOMY AND PHYSIOLOGY. 73 

posito the attachment of the broad ligament, by a deep 
notch. In adult males this border usually corresponds with 
the margin of the ribs; but in women and children it usu- 
ally projects below the ribs. Thus it is situated in the 
highest part of the abdominal cavity on the right side im- 
mediately beneath the diaphragm, in contact with the upper 
portion of the pyloric end of the stomach, the duodenum, 
right kidney, and transverse colon. 

Its large size, complex structure, and its relations to the 
alimentary canal are evidence that it has an important place 
in the economy of human life. For all this its functions 
are very imperfectly understood. The secretion formed 
within it is called bile, which is retained in a small sac 
called the gall -bladder, and, as occasion requires, it passes 
through the common duct of the liver, called ductus com- 
munis choledochus, to the duodenum to mingle with the 
food in course of digestion. 

At this stage in the digestive progress the chyme from 
the stomach is in contact with the bile from the liver and 
the juice from the pancreas by which it is reduced to a 
condition in which the nutritive and innutritive qualities 
of the food may be separated and properly appropriated by 
the work to be accomplished in its passage through the 
jejunum and ileum. 

It is quite satisfactorily established that the function of 
the pancreatic juice is to convert the fatty elements of the 
food into chyle, and so prepare it for absorption by the lac- 
teals that it may be passed into the blood. But exactly 
what the function of the bile is, in this connection, baffles 
the skill of the physiologists. It is certain, however, as 



74 A COMPEND OF 

numerous experiments on the lower animals have proven, 
that its presence is indispensable to the completion of the 
digestion and assimilation in the human organism, as death 
will speedily ensue when it is absent. 

The small intestine, from the pylorus down, has, covering 
its internal surface, two classes of glands from which ex- 
udes a fluid, the chief function of which is supposed to be 
to lubricate the inner surface. These glands are called 
Brunner's glands, occupying the upper portion of the duo- 
denum, and Lieberkuhn follicles, covering the rest of the 
intestine. 

In addition to these, the absorption of the digested food, 
which is the main office performed by the small intestine, 
is provided for by a special structure of its mucous mem- 
brane. The apparatus consists in an abundance of minute 
eminences or prolongations, the so-called villi of the small 
intestine, so closely set over its surface as to give it a char- 
acteristic velvety appearance. They are found throughout 
this part of the alimentary canal, from the p}dorus to the 
free border of the ileo-cgecal valve, most abundant in the 
duodenum and jejunum, rather less so in the ileum. 

The villi are the active agents in the process of absorp- 
tion ; there must be at least from fifteen to twenty millions 
of them in the intestine. By their abundance, as well as 
by their projecting form, they multiply the extent of con- 
tact of the digested fluids with the mucous membrane, and 
increase, in a corresponding degree, the activity of absorp- 
tion. They hang out into the nutritious, semi-fluid mass 
in the intestinal cavity, as the roots of a tree penetrate the 
soil; and they imbibe its liquefied portions with a rapidity 



ANATOMY AND PHYSIOLOGY. 75 

which is in proportion to their extent of surface and the 
movement of the circulation (XXX.). 

The final absorption of the digestive fluids is accom- 
plished mainly by the blood-vessels of the intestinal villi. 
Their situation,, their numbers, and the rapid movement 
of the blood are all favorable conditions for the performance 
of this function. The capillary plexus of each villus is 
situated, in its superficial part, immediately beneath the 
epithelial cells, so that the absorbed fluids, after passing 
through the epithelial layer, come at once in contact with 
the vascular network. The extension of absorbing surface, 
from the division and inosculation of these vessels, and 
the renovation of their fluids by the movement of the cir- 
culation, provide for their constant activity, and drain 
away the absorbed fluids from the interior of the villus as 
fast as they are taken up by its surface. 

The entrance of digested materials into the blood-ves- 
sels of the intestine has been demonstrated. After the 
digestion of food containing albuminous and starchy in- 
gredients, both glucose and peptone are met with in the 
blood of the portal vein. Emulsioned fatty matters may 
also be followed in their passage through the same chan- 
nels by the chylous aspect which they communicate to the 
portal blood. A variety of observers (Lehmann, Schultz, 
Simon), in examining the blood from different parts of the 
body, have also found the blood of the portal system con- 
siderably richer in fat than that of the arteries or of other 
veins, particularly while digestion is going on. (This will 
be further treated in the chapter on the circulation of the 
blood.) 



j6 A COMPEND OF 

The absorption of digested materials, particularly of the 
fatty matters, is also accomplished by the lacteals of the 
small intestine. These vessels are part of the great lym- 
phatic system, which is distributed everywhere — in the in- 
teguments of the head, the parietes of the trunk, the limbs, 
and in the glands, muscles, and mucous membranes — 
throughout the body. Originating in the tissues of these 
organs, they pass from the periphery toward the centre, 
converging and uniting with each other like the veins, and 
passing at various points through the lymphatic glands 
(XLII., b, b, etc.; XLIV., k ; XLYL, b). 

The fluid generally contained in these vessels is the 
" lymph." It is a colorless or slightly-yellowish transpar- 
ent liquid, absorbed by the lymphatic vessels from the va- 
rious tissues, and containing, besides water and saline mat- 
ters, a small quantity of fibrin and albumin. 

The lymphatic vessels of the intestine originate in the 
villi as longitudinal spaces lined with flattened epithelial 
cells, becoming provided, after a short distance, with trans- 
parent elastic coats, like those of the capillary blood-ves- 
sels. On emerging from the villi they become part of the 
lymphatic plexus, from which the main branches pass be- 
tween the layers of the mesentery, from the intestine 
toward the posterior part of the abdomen. In this part of 
their course they inosculate with each other by transverse 
branches, and pass through several ranges of mesenteric 
glands, representing the lymphatic glands of the abdomi- 
nal cavity. Near the attached portion of the mesentery, 
on the right side of the abdomen, about the level of the 
second lumbar vertebra, they terminate in a sacular dila- 



ANATOMY AND PHYSIOLOGY. 77 

tation, the " receptaculum ehyli." From this point the 
thoracic duct passes upward through the chest, crossing 
obliquely from right to left, and terminating in the left 
subclavian vein at its junction with the jugular of the 
same side (XV., 17; XVI., 17, 45, 46, 51; XXXV.). 

When the work of absorption by the villi and lacteals is 
completed, the remaining matter passes right-hand side of 
the abdomen, through an orifice between two valvular folds 
called the Ileo-caecal valve, into a large sac called the 
Caecum, at the commencement of the colon, or large intes- 
tine. Below this orifice, attached to the Caecum and open- 
ing into it, is a narrow worm-shaped tube called the appen- 
dix vermiformis, which varies from three to six inches in 
length, about the diameter of a goose-quill. It is usually 
directed upward and inward behind the Caecum, coiled 
upon itself, and terminates in a blunt point. Its canal is 
small and communicates with the Caecum by an orifice which 
is sometimes guarded by an incomplete valve. The vital 
functions of this organ, if it have any, are not- known; but 
it sometimes occurs that small portions of undigested solid 
matter, such as fruit seeds, become lodged in it and produce 
fatal results. These instances, however, are very rare. 

The large intestine, called the Colon, commencing at the 
Caecum, passes upward to the lower side of the liver, and 
then transversely to the left side beneath the liver and the 
stomach, and then downward to form the sigmoid flexure 
at the commencement of the rectum, thus forming an arch 
inclosing the small intestine. Its three divisions are 
called the ascending, transverse, and descending colon. 
The function of this organ is to absorb the superfluous 



78 A COMPEND OF 

fluids from the remnants of the alimentary mass (XIII., 
XXIV.). 

The Peritoneum is a serous membrane, and, like all 
membranes of this class, a shut sac. In the female, how- 
ever, it is not completely closed. It partially invests all 
the viscera contained in the abdominal and pelvic cavities, 
forming the visceral layer of the membrane; it is then re- 
flected upon the internal surface of the parietes of those 
cavities, forming the parietal layer. 

The great omentum, covering the upper portion of the 
intestines, and the lesser omentum, containing the hepatic 
vessels and nerves, with the mesentery, are embraced in 
this serous membrane. 

The affection called peritonitis is a diseased condition 
of this membrane, and its intimate relation with the entire 
abdominal viscera necessarily induces general sympathy 
with its condition, and suggests serious results. 

Hernia, or Rupture, is produced by excessive pressure of 
the lower portion of the intestines on the thin muscular 
tissues of the abdomen, generally in the vicinity of the 
groin, by which a small opening is made in its walls, and a 
portion of the intestine, .covered with peritoneum, which 
forms a sac, is forced through. This condition sometimes 
exists for a long time unnoticed without serious results; 
but if the hernial sac and its contents remain protruded 
and there is constriction of the muscular fibres at its neck, 
so that the passage through the intestine is closed, a speedy 
surgical operation is necessary or fatal results will soon 
follow. Such an operation requires great skill and thorough 
anatomical knowledge of the parts, as the hernia is gener- 



ANATOMY AND PHYSIOLOGY. Jg 

ally in close proximity to the iliac and femoral blood- 
vessel. 

BESPIKATION. 

The most constant phenomenon presented by living 
organisms, both animal and vegetable, is the absorption of 
oxygen. This substance, either in gaseous form as a con- 
stituent of the atmosphere, or dissolved in water or other 
liquids, is indispensably requisite for the manifestation of 
vital phenomena. Oxygen is diffused everywhere over the 
surface of the earth, forming rather more than one-fifth 
part of the volume of the atmosphere, and exists in solu- 
tion in greater or less abundance in the water springs, 
rivers, lakes, and seas. Animals and plants, accordingly, 
whether living in the air or in the water, are surrounded by 
media in which this substance is present. Even parasitic 
organisms inhabiting other living bodies, though not in 
immediate contact with oxygen, are supplied with nutri- 
tious fluids which have themselves been exposed to its in- 
fluence. Respiration consists in the process by which oxy- 
gen penetrates the substance of living organisms, and the 
changes which accompany or follow its introduction. 

(LXXXIII., LXXXIV., LXXXV.) The respiratory 
apparatus in man begins with the larynx (XV., 10, 11, 12), 
communicating through the glottis with the pharynx. 
Then follows the trachea, a membranous tube with carti- 
laginous rings, dividing into the right and left bronchi 
(XII., 13). These divide in turn into secondary and terti- 
ary bronchi; the subdivision continuing, and the bronchial 
tubes growing constantly smaller and more numerous. 



8o A COMPEND OF 

When finally reduced to a diameter of 0.012 of an inch, 
they are composed only of a thin membrane, lined with 
pavement epithelium, resting upon an elastic fibrous layer. 
They are then known as the " ultimate bronchial tubes." 

Each ultimate bronchial tube terminates in a pyramidal- 
shaped islet of pulmonary tissue, about 0.08 of an inch in 
diameter, termed a " pulmonary lobule." It consists of a 
vascular membrane in the form of a sac, the cavity of which 
is divided into secondary compartments by thin partitions 
projecting from its inner surface. These secondary cavi- 
ties are the " pulmonary vesicles." They have an average 
diameter of about 0.01 of an inch; but owing to the disten- 
sibility and elasticity of their walls, they are capable of di- 
lating to double or triple their former size and returning 
to their original dimensions when the distending force is 
removed. There is reason to believe that during life they 
alternately expand and retract, as the lungs are filled and 
emptied with the movements of respiration. 

Each vesicle is surrounded by capillary blood-vessels, 
which penetrate its partition walls and are thus exposed 
on both sides to the influence of the air in the pulmonary 
cavities. The abundant elastic tissue in the walls of the 
vesicles and in the interlobular spaces gives to the lungs 
their property of resiliency. The pavement epithelium 
lining the ultimate bronchial tubes extends into the lobules 
and vesicles, forming a continuous investment of their in- 
ternal surface. 

The extensive involution of the respiratory membrane 
resulting from the multiplication of the bronchial tubes 
and vesicles in the kings, increases in a high degree the 



ANATOMY AND PHYSIOLOGY. Si 

activity of respiration; since the blood in the capillary 
vessels, distributed in thin layers over so large a surface, 
in immediate proximity to the air in the pulmonary cavi- 
ties, is placed under the most favorable conditions for rapid 
arterialization. 

THE THOEAX. 

The Thorax (XXXVIIL, XLII.) is a conical framework 
formed partly of bones and partly of the soft tissues by 
which they are connected together. It is supported and 
its back part is formed by the middle or dorsal region of 
the spine. It is narrow above, broad below, flattened be- 
fore and behind, and somewhat cordiform in a transverse 
section. It is bounded in front by the sternum (XXXVIIL, 
31, 32, 33), the six upper costal cartilages, the ribs, and 
intercostal muscles; at the sides by the ribs and intercos- 
tal muscles; and behind by the same structures and the 
dorsal portions of the vertebral column. 

The superior opening of the thorax is bounded on each 
side by the first rib; in front by the upper border of the 
sternum; and behind by the first dorsal vertebra. It is 
broader from side to side than from before backward, and 
its direction is backward and upward. 

The lower opening or base is bounded in front by the en- 
siform cartilage; behind by the last dorsal vertebra; and 
on each side by the last rib, the diaphragm filling in the in- 
tervening space (XXXVIIL, 31, 32, 33). 

The parts which pass through the upper opening of the 

thorax are (X.), from before backward, the sterno-hyoid 

and sterno-thyroid muscles, the remains of the thymus 
6 



82 A COMPEND OF 

gland, the trachea, oesophagus, thoracic duct, and the Ion- 
gus colli muscles of each side; on the sides the arteria in- 
nominata, the left common carotid and left subclavian ar- 
teries, the internal mammary and superior intercostal 
arteries, the right and left venae innominatae and the infe- 
rior thyroid veins, the pneumogastric, sympathetic, phrenic, 
and cardiac nerves, the anterior branch of the first dorsal 
nerve, and the recurrent laryngeal nerve of the left side. 
The apex of each lung, covered by the pleura, also projects 
through this aperture, a little above the margin of the first 
rib. 

The viscera contained in the thorax are (X., 5, 6) the 
heart, inclosed in its membranous bag, the pericardium, 
and the lungs, invested by the pleura. 

ORGANS OF RESPIRATION. 

THE LARYNX. 

(XII., f., LXXXIIL, LXXXIV., LXXXV.) 

The Larynx is the organ of voice, placed at the upper 
part of the air-passage. It is situated between the trachea 
and base of the tongue, at the upper forepart of the neck, 
where it forms a considerable projection in the middle line. 
On either side of it lie the great vessels of the neck; behind 
it forms part of the boundary of the pharynx (XXXIII., 
6, 8), and is covered by the mucous membrane lining the 
cavity. 

The Larynx is narrow and cylindrical below, but broad 
above, where it presents the form of a triangular box, flat- 



ANATOMY AND PHYSIOLOGY. 83 

tened behind and at the sides, while in front it is bounded 
by a prominent vertical ridge. It is composed of cartilages, 
which are connected together by ligaments and moved by 
numerous muscles; the interior is lined by mucous mem- 
brane and supplied with vessels and nerves. 

The Cartilages of the larynx are nine in number, three 
single and three pairs, one Thyroid, Cricoid, and Epiglot- 
tis; and two each Arytenoid, Cornicula Laryngis, and Cu- 
neiform (LXXXIIL). 

The Thyroid (6) is the largest cartilage of the larynx. 
It consists of two lateral lamella? or alae, united at an acute 
angle in front, forming a vertical projection in the middle 
line which is prominent above, and called the pomum 
Adami. 

The Cricoid Cartilage (9) is so called from its resemblance 
to a signet ring. It is smaller but thicker and stronger 
than the thyroid cartilage, and forms the lower and back 
part of the cavity of the larynx. 

The Arytenoid Cartilages (LXXXV., 5) are so called 
from the resemblance they bear, when approximated, to 
the mouth of a pitcher. They are two in number, and 
situated at the upper border of the cricoid cartilage, at the 
back of the larynx. Each cartilage is pyramidal in form. 

The cuneiform cartilages are two small, elongated car- 
tilaginous bodies, placed one on each side, in the fold of 
mucous membrane which extends from the apex of the 
arytenoid cartilage to the side of the epiglottis. 

The epiglottis (1) is a thin lamella of fibro-cartilage, of 
a yellowish color, shaped like a leaf, and placed behind the 
tongue in front of the superior opening of the larynx. 



84 . A COMPEND OF 

During respiration its direction is vertically upward, its 
free extremity curving forward toward the base of the 
tongue ; but when the larynx is drawn up beneath the base 
of the tongue, during deglutition, it is carried downward 
and backward, so as to completely close the opening of the 
larynx. Its free extremity is broad and rounded ; its at- 
tached end is long and narrow, and connected to the reced- 
ing angle between the twoalae of the thyroid cartilage, just 
below the median . notch, by a long, narrow, ligamentous 
band, the thy ro-epi glottic ligament. It is also connected 
to the posterior surface of the body of the hyoid bone by 
an elastic ligamentous band, the hyo-epiglottic ligament 
(LXXXIV.). 

The epiglottis, cuneiform cartilages, and cornicula laryn- 
gis are composed of yellow cartilage, which shows little 
tendency to ossification; but the other cartilages resem- 
ble in structure the costal cartilages, becoming more or 
less ossified in old age. 

The ligaments of the larynx are extrinsic, those connect- 
ing the thyroid cartilage with the os hyoides ; and intrinsic, 
those which connect the several cartilaginous segments to 
each other (LXXXIIL, LXXXV. contain external figures 
in full). 

The ligaments connecting the thyroid cartilage with the 
os hyoides are three in number : the thyro-hyoid membrane 
and two lateral thyro-hyoid ligaments. 

The thyro-hyoid membrane is attached below to the upper 
border of the thyroid cartilage, and above to the upper bor- 
der of the inner surface of the hyoid bone. In the middle 
it is pierced by the superior laryngeal vessels and nerve. 



ANATOMY AND PHYSIOLOGY. 85 

The two lateral tlnjro-Injoid ligaments pass between the 
superior cornua of the thyroid cartilage and the extremi- 
ties of the greater cornua of the hyoid bone. 

The crico-thyroid membrane connects together the con- 
tiguous margins of the thyroid and cricoid cartilages, and 
extends from the superior border of the cricoid cartilage to 
the inferior margin of the true vocal cords, with which it 
is closely united in front. 

A capsular ligament incloses the articulation of the in- 
ferior cornu of the thyroid with the cricoid cartilage on 
each side. 

The hyo-epiglottic ligament extends from the anterior 
surface of the epiglottis, near its apex, to the posterior 
surface of the body of the hyoid bone. 

The thyroepiglottic ligament connects the apex of the 
epiglottis with the receding angle of the thyroid cartilage, 
immediately beneath the median notch, above the attach- 
ment of the vocal cords. 

Interior of the Larynx (LXXXIV.). The superior aper- 
ture of the larynx is a triangular or cordiform opening, 
wide in front, narrow behind, and sloping obliquely down- 
ward and backward. It is bounded in front by the epiglot- 
tis; behind by the apices of the arytenoid cartilages and 
the cornicula laryngis; and laterally by a fold of mucous 
membrane, inclosing ligamentous and muscular fibres, 
stretched between the sides of the epiglottis and the apex 
of the arytenoid cartilages; these are the aryteno-epiglotti- 
dean folds, on the margins of which the cuneiform carti- 
lages form a more or less distinct whitish prominence. 

The cavity of the larynx extends from the aperture be- 



86 A COMPEND OF 

hind the epiglottis to the lower border of the cricoid car- 
tilage. It is divided into two parts by the projection inward 
of the vocal cords and the thyro-arytenoid muscles; between 
the two cords is a long, narrow triangular fissure or chink, 
the glottis or rima glottidis. The portion of the cavity of 
the larynx above the glottis is broad and triangular in 
shape above, and corresponds to the interval between the 
alae of the thyroid cartilage ; the portion below the glottis 
is at first of an elliptical, and lower down of a circular 
form. 

The glottis is the interval between the inferior or true 
vocal cords. The two superior or false vocal cords are 
placed above the latter, and are formed almost entirely 
by a folding inward of the mucous membrane; while the 
two inferior or true vocal cords are thick, strong, and 
formed partly by mucous membrane and partly by liga- 
mentous fibres. Between the true and false vocal cords, 
on each side, is an oval depression, the sinus, or ventricle 
of the larynx, which leads upward on the outer side of the 
superior vocal cord, into a caecal pouch of variable size, the 
sacculus laryngis. 

The glottis {rima glottidis) is a narrow fissure or chink 
between the inferior or true vocal cords. It is the narrow- 
est part of the cavity of the larynx, and corresponds to the 
lower level of the arytenoid cartilages. Its length in the 
male measures rather less than an inch, its breadth when 
dilated varying at its widest part from a third to half an 
inch. In the female these measurements are somewhat 
less. The form of the glottis varies. In its half-closed 
condition it is a narrow fissure, a little enlarged and 



ANATOMY AND PHYSIOLOGY. 87 

rounded behind. In quiet breathing it is widely open, 
somewhat triangular, the base of the triangle directed 
backward, and corresponding to the space between the sep- 
arated arytenoid cartilages. In forcible expiration it is 
smaller than during inspiration. When sound is produced 
it is more narrowed, the margins of the arytenoid carti- 
lages being brought into contact, and the edges of the vocal 
cords approximated and made parallel, the degree of ap- 
proximation and tension corresponding to the height of 
the note produced. 

The superior or false vocal cords, so called because they 
are not directly concerned in the production of the voice, 
are two folds of mucous membrane, inclosing a delicate, 
narrow fibrous band, the superior tliyro- arytenoid ligament. 

This ligament consists of a thin band of elastic tissue, 
attached in front to the angle of the thyroid cartilage be- 
low the epiglottis, and behind to the anterior surface of 
the arytenoid cartilage. The lower border of this ligament, 
inclosed in mucous membrane, forms a free crescentic 
margin, which constitutes the upper boundary of the ventri- 
cle of the larynx. 

The inferior or true vocal cords, so called from their be- 
ing concerned in the production of sound, are two strong 
fibrous bands (inferior tliyro-arytenoid ligaments) covered 
on their surface by a thin layer of mucous membrane. 
Each ligament consists of a band of yellow elastic tissue, 
attached in front to the depression between the two alee of 
the thyroid cartilage, and behind to the anterior angle of 
the base of the arytenoid. Its lower border is continuous 
with the thin lateral part of the crico- thyroid membrane. 



88 A COMPEND OF 

Its upper border forms the lower boundary of the ventricle 
of the larynx. Externally, the Thyro-arytaenoideus mus- 
cle lies parallel with it. It is covered internally by mucous 
membrane, which is extremely thin and closely adherent 
to its surface. 

The ventricle of the larynx is an oblong fossa, situated 
between the superior and inferior vocal cords on each side, 
and extending nearly their entire length. This fossa is 
bounded above by the free crescentic edge of the superior 
vocal cord ; below by the straight margin of the true vocal 
cord; externally by the corresponding Thyro-arytsenoideus 
muscle. The anterior part of the ventricle leads up by a 
narrow opening into a caecal pouch of mucous membrane 
of variable size, called the laryngeal pouch. 

The sacculus laryngis, or laryngeal pouch, is a membra- 
nous sac placed between the superior vocal cord and the 
inner surface of the thyroid cartilage, occasionally extend- 
ing as far as its upper border; it is conical in form and 
curved slightly backward, like a Phrygian cap. On the 
surface of its mucous membrane are the openings of sixty 
or seventy small follicular glands, which are lodged in the 
submucous areolar tissue. This sac is inclosed in a fibrous 
capsule continuous below with the superior thyro-arytenoid 
ligament; its laryngeal surface is covered by the Arytaeno- 
epiglottideus inferior muscle (Compressor sacculilaryngis), 
while its exterior is covered by the Thyro-epiglottideus 
muscle. These muscles compress the sacculus laryngis, 
and discharge the secretion it contains upon the chordse 
vocales, the surface of which it is intended to lubricate. 

Muscles. The intrinsic muscles of the larynx are eight 



ANATOMY AND PHYSIOLOGY. 89 

in number, five of which are the muscles of the chordae 
vocales and rima giottidis; three are connected with the 
epiglottis. 

The five muscles of the chordae vocales and rima giottidis 
are the Crico-thyroid, Crico-arytaenoideus posticus, Crico- 
arytrenoideus lateralis, Arytgenoideus, and Thyro-arytaenoi- 
deus. 

The muscles of the epiglottis are the Thyro-epiglottideus 
and Arytaeno-epiglottideus, superior and inferior. 

The muscles that open the glottis are the Crico-arytae- 
noidei postici, and those which close it are the Arytaenoi- 
deus and the Crico-arytaenoidei laterales. The muscles 
which regulate the tension of the vocal cords are the Crico- 
thyroids, which stretch and elongate them, and the Thyro- 
arytaenoidei, which relax and shorten them. The Thyro- 
epiglottideus is a depressor of the epiglottis, and the 
Arytaeno-epiglottei constrict the superior aperture of the 
larynx, compress the sacculi laryngis, and empty them of 
their contents. 

The Mucous Membrane of the larynx is continuous above 
with that lining the mouth and the pharynx, and is pro- 
longed through the trachea and bronchi into the lungs. It 
lines both surfaces of the epiglottis, to which it is closely 
adherent, and forms the aryteno-epiglottidean folds which 
encircle the superior aperture of the larynx. It lines the 
whole of the cavity of the larynx ; forms, by its reduplica- 
tion, the chief part of the superior, or false, vocal cord; 
and from the ventricle is continued into the sacculus 
laryngis. It is then reflected over the true vocal cords, 
where it is thin and very intimately adherent \ covers the 



90 A COMPEND OF 

inner surface of the crico-thyroid membrane and cricoid 
cartilage, and is ultimately continuous with the lining 
membrane of the trachea. It is covered with columnar 
ciliated epithelium below the superior vocal cord; but 
above this point the cilia are found only in front, as high 
as the middle of the epiglottis. In the rest of its extent 
the epithelium is of the squamous variety. 

Glands. The mucous membrane of the larynx is fur- 
nished with numerous muciparous glands. The orifices are 
found in nearly every part; they are very numerous upon 
the epiglottis, being lodged in little pits in its substance; 
they are also found in large numbers along the posterior 
margin of the aryteno-epiglottidean fold, in front of the 
arytenoid cartilages, where they are termed the arytenoid 
glands. They exist also in large numbers upon the inner 
surface of the sacculus laryngis. None is found on the 
vocal cords. 

Vessels axd Nerves. The arteries of the larynx are 
the laryngeal branches derived from the superior and in- 
ferior thyroid. The veins empty themselves into the su- 
perior, middle, and inferior thyroid veins. The lymphatics 
terminate in the deep cervical glands. The nerves are the 
superior laryngeal and the inferior or recurrent laryngeal 
branches of the pneumogastric nerves, joined by filaments 
from the sympathetic. The superior laryngeal nerves sup- 
ply the mucous membrane of the larynx and the Crico- 
thyroid muscles. The inferior laryngeal nerves supply the 
remaining muscles. The Arytenoid muscle is supplied by 
both nerves. 



ANATOMY AND PHYSIOLOGY. 91 

THE TEACHEA. 

(XII., g.) 

The Trachea or windpipe is a cartilaginous and membra- 
nous cylindrical tube, flattened posteriorly, which extends 
from the lower part of the larynx, on a level with the fifth 
cervical vertebra, to opposite the third dorsal, where it di- 
vides into the two bronchi (13), one for each lung. The 
trachea measures about four inches and a half in length; 
its diameter from side to side is from three-quarters of 
an inch to an inch, being always greater in the male than 
in the female. 

The anterior surface of the trachea is convex, and cov- 
ered in the neck, from above downward, by the isthmus 
of the thyroid gland, the inferior thyroid veins, the arteria 
thyroidea ima, the sterno-hyoid and sterno-thyroid muscles, 
the cervical fascia (in the interval between those muscles), 
and, more superficially, by the anastomosing branches be- 
tween the anterior jugular veins; in the thorax it is cov- 
ered from before backward by the first piece of the sternum, 
the remains of the thymus gland, the arch of the aorta, 
the innominate and left carotid arteries, and the deep car- 
diac plexus. It lies upon the oesophagus, which is directed 
to the left near the arch of the aorta; laterally, in the neck, 
it is in relation with the common carotid arteries, the 
lateral lobes of the thyroid gland, the inferior thyroid ar- 
teries, and recurrent laryngeal nerves; and in the thorax 
it lies in the interspace between the pleurae, having the 
pneumogastric nerve on each side of it. 



92 A COMPEND OF 

The Right Bronchus, wider, shorter, and more horizon- 
tal in direction than the left, is about an inch in length, 
and enters the right lung, opposite the fourth dorsal ver- 
tebra. The vena azygos arches over it from behind, and 
the right pulmonary artery lies below and then in front 
of it. 

The Left Bronchus is smaller, more oblique, and longer 
than the right, being nearly two inches in length. It 
enters the root of the left lung, opposite the fifth dorsal 
vertebra, about an inch lower than the right bronchus. 
It crosses, in front of the oesophagus, the thoracic duct 
and the descending aorta, passes beneath the arch of the 
aorta, and has the left pulmonary artery lying at first 
above and then in front of it. If a transverse section is 
made across the trachea a short distance above its point 
of bifurcation and a bird's-eye view taken of its interior, 
the septum placed at the bottom of the trachea and sepa- 
rating the two bronchi will be seen to occupy the left of 
the median line, so that any solid body dropping into the 
trachea would naturally be directed toward the right bron- 
chus, and this tendency is undoubtedly aided by the larger 
size of this tube, as compared with its fellow. This fact 
serves to explain why a foreign substance in the trachea 
generally falls into the right bronchus. 

The trachea is composed of imperfect cartilaginous rings, 
fibrous membrane, muscular fibres, mucous membrane, and 
glands. 

The Cartilages vary from sixteen to twenty in number; 
each forms an imperfect ring, which surrounds about two- 
thirds of the cylinder of the trachea, being imperfect be- 



ANATOMY AND PHYSIOLOGY. 93 

hind, where the tube is completed by fibrous membrane. 
The cartilages are placed horizontally above each other, 
separated by narrow membranous intervals. 

Vessels and Nerves. The trachea is supplied with blood 
by the inferior thyroid arteries. The veins terminate in 
the thyroid venous plexus. The nerves are derived from 
the pneumogastric and its recurrent branches and from the 
sympathetic. 

THE PLEUK^E. 

Each lung is invested, upon its external surface, by a 
delicate serous membrane, the Pleura, which incloses the 
organ as far as its root, and is then reflected upon the in- 
ner surface of the thorax. The portion investing the sur- 
face of the lung is called the pleura pulmonalis, while that 
which lines the inner surface of the chest is called the 
pleura costalis. The interspace or cavity between these 
two layers is called the cavity of the pleura. Each pleura 
is therefore a shut sac, one occupying the right, the other 
the left half of the thorax; and they are perfectly separate, 
not communicating with each other. The two pleurae do 
not meet in the middle line of the chest, excepting at one 
point in front, an interspace being left between them 
which contains a]l the viscera of the thorax except the 
lungs; this is the mediastinum. ■ 

Commencing at the sternum, the pleura passes outward, 
covers the costal cartilages, the inner surface of the ribs 
and intercostal muscles, and at the back part of the thorax 
passes over the thoracic ganglia and their branches, and 
is reflected upon the sides of the bodies of the vertebrae, 



94 A COMPEND OF 

where it is separated by a narrow interspace, the posterior 
mediastinum, from the opposite pleura. From the verte- 
bral column the pleura passes to the side of the pericar- 
dium, which it covers to a slight extent; it then 'covers 
the back part of the root of the lung, from the lower bor- 
der of which a triangular fold descends vertically by the 
side of the posterior mediastinum to the Diaphragm. This 
fold is the broad ligament of the lung, the hgamentum 
latum pulmonis, and serves to retain the lower part of that 
organ in position. From the root the pleura may be traced 
over the convex surface of the lung, the summit and base, 
and also over the sides of the fissures between the lobes. 
It covers its anterior surface and the front part of its root, 
and is reflected upon the side of the pericardium to the 
inner surface of the sternum. Beloiv, it covers the surface 
of the Diaphragm. Above, its apex^projects, in the form of 
a cul-de-sac, through the superior opening of the thorax, into 
the neck, extending about an inch above the margin of the 
first rib, and receives the summit of the corresponding 
lung; this sac is strengthened by a dome-like expansion of 
fascia, derived from the lower part of the Scaleni muscles 
(LXXXVIII. The dark line is the cavity of the pleurae). 

A little above the middle of the sternum, the contiguous 
surfaces of the two pleurae are sometimes in contact for a 
slight extent; but above and below this point the interval 
left between them forms the anterior mediastinum. 

The inner surface of the pleura is smooth, polished, and 
moistened by a serous fluid; its outer surface is adherent 
to the surface of the lung and to the pulmonary vessels 
as they emerge from the pericardium; it is also adherent 



ANATOMY AND PHYSIOLOGY. 95 

to the upper surface of the Diaphragm; throughout the 
rest of its extent it is somewhat thicker, and may be sepa- 
rated from the adjacent parts with great facility. 

Vessels and Nerves. The arteries of the pleura are de- 
rived from the intercostal, the internal mammary, the 
phrenic, inferior thyroid, thymus, pericardiac, and bron- 
chial. The veins correspond to the arteries. The lympha- 
tic* are very numerous. The nerves are derived from the 
phrenic and sympathetic. 

MEDIASTINUM. 

The Mediastinum is the space left in the median line of 
the chest by the non-approximation of the two pleurae. It 
extends from the sternum in front to the spine behind, 
and contains all the viscera of the thorax, excepting the 
lungs. It is subdivided, for convenience of description, into 
the anterior, middle, and posterior. 

THE LUNGS. 

(1, 5; XII.) 

The Lungs are the essential organs of respiration; they 
are two in number, placed one in each of the lateral cavi- 
ties of the chest, separated from each other by the heart 
and other contents'of the mediastinum. Each lung is coni- 
cal in shape and the apex forms a tapering cone, which 
extends into the root of the neck a little above the level of 
the first rib. The base is broad, concave, and rests upon 
the convex surface of the Diaphragm (XVL, 27). The ex- 



g6 A COMPEND OF 

ternal or thoracic surface is smooth, convex, and corre- 
sponds to the form of the cavity of the chest, being deeper 
behind than in front. The inner surface is concave. It . 
presents in front a depression corresponding to the con- 
vex surface of the pericardium, and behind, a deep fissure 
(the hilum pulmonis) which gives attachment to the root 
of the lung. The posterior border is rounded and broad, 
and is received in the deep concavity on either side of the 
spinal column. It is much longer than the anterior bor- 
der, and projects below between the ribs and the diaphragm. 

The anterior border is thin and sharp and overlaps the 
front of the pericardium. 

Each lung is divided into two lobes, an upper and lower, 
by a long and deep fissure, which extends from the upper 
part of the posterior border of the organ, about three 
inches from its apex, downward and forward to the lower 
part of its anterior border. This fissure penetrates nearly 
to the root. In the right lung the upper lobe is partially 
divided by a second and shorter fissure, which extends from 
the middle of the preceding, forward and upward, to the 
anterior margin of the organ, marking off a small triangu- 
lar portion, the middle lobe; thus there are really three 
lobes to the right lung and but two to the left. 

The right lung is the larger; it is broader than the left, 
owing to the inclination of the heart to the left side; it is 
also shorter by an inch, in consequence of the Diaphragm 
rising higher on the right side to accommodate the liver. 

XII. A little above the middle of the inner surface of 
each lung, and nearer its posterior than its anterior border, 
is its root, by which the lung is connected to the heart and 



ANATOMY AND riTYSTOLOGV. 97 

the trachea. The root is formed by the bronchial tube 
(13), the pulmonary artery (11), the pulmonary veins (12), 
the bronchial arteries and veins, the pulmonary plexus of 
nerves, lymphatics, bronchial glands, and areolar tissue, all 
of which are inclosed by reflection of the pleura. The 
root of the right lung lies behind the superior vena cava 
(10) and upper part of the right auricle (2), and below the 
vena azygos. That of the left lung passes beneath the arch 
of the aorta (6) and in front of the descending aorta; the 
phrenic nerve and the anterior pulmonary plexus lie in 
front of each, and the pneumogastric and posterior pul- 
monary plexus behind each. 

The substance of the lung is of a light, porous, spongy 
texture; it floats in water and crepitates when handled, 
owing to the presence of air in the tissue; it is also highly 
elastic; hence the collapsed state of these organs when they 
are removed from the closed cavity of the thorax. 

The lungs are composed of an external serous coat, a 
subserous areolar tissue, and the pulmonary substance or 
parenchyma. The serous coat is derived from the pleura; 
it is thin, transparent, and invests the entire organ as far 
as the root. 

The subserous areolar tissue contains a large propor- 
tion of elastic fibres; it invests the entire surface of the 
lung, and extends inward between the lobules. 

The parenchyma is composed of lobules, which, although 
closely connected together by an interlobular areolar tis- 
sue, are quite distinct from one another. The lobules vary 
in size ; those on the surface are large, of a pyramidal form, 
the base turned toward the surface; those in the interior 
7 



98 A COMPEND OF 

smaller and of various forms. Each lobule is composed 
of one of the ramifications of the bronchial tube and its 
terminal air-cells and of the ramifications of the pulmo- 
nary and bronchial vessels, lymphatics, and nerves : all of 
these structures being connected together by areolar fibrous 
tissue. 

The bronchus, upon entering the lung, divides and sub- 
divides dichotomously throughout the entire organ. Each 
of the smaller divisions of the bronchi enters a pulmonary 
lobule, and, again subdividing, ultimately terminates in 
the intercellular passages and air-cells of which the lobule 
is composed. 

Within the lungs the bronchial tubes are circular, not 
flattened, and their constituent elements present the fol- 
lowing peculiarities of structure : 

The cartilages are not imperfect rings, bat consist of 
thin laminae, of varied form and size, scattered irregularly 
along the sides of the tube, being most distinct at the 
points of division of the bronchi. Beyond these the tubes 
are wholly membranous. The fibrous coat and the longi- 
tudinal elastic fibres are continued into the smallest rami- 
fications of the bronchi. The muscular coat is disposed 
in the form of a continuous layer of annular fibres, which 
may be traced upon the smallest bronchial tubes; they 
consist of the unstriped variety of -muscular fibre. The 
mucous membrane lines the bronchi and its ramifications 
throughout, and is covered with columnar ciliated epi- 
thelium. 

The air-cells, or alveoli, are small polyhedral alveolar 
recesses, separated from each other by thin septa and com- 



ANATOMY AND PHYSIOLOGY. 99 

mxmicating freely with the intercellular passages or air- 
sacs. They are well seen on the surface of the lung, being 
largest on the surface, at the thin borders, and at the apex, 
and smallest in the interior. 

At the termination of the bronchial tubes, in the in- 
tercellular passages, their constituent elements become 
changed ; their walls are formed by an interlacing of the 
longitudinal elastic bundles with fibrous tissue; the mus- 
cular fibres disappear, and the mucous membrane becomes 
thin and delicate and lined with' a layer of squamous epi- 
thelium. The latter membrane lines the air-cells, and 
forms by its reduplications the septa intervening between 
them. 

The Pulmonary Artery (XII., 11) conveys the venous 
blood to the lungs. It dhides into branches which ac- 
company the bronchial tubes, and terminates in a dense 
capillary network upon the walls of the intercellular pas- 
sages and air-cells. From this network the radicles of the 
pulmonary veins arise; coalescing into large branches, they 
accompany the arteries, and return the blood, purified by 
its passage through, the capillaries, to the left auricle of 
the heart (4). In the lung, the branches of the pulmonary 
artery are usually above and in front of a bronchial tube, 
the vein below. 

The Pulmonary Capillaries form plexuses which lie im- 
mediately beneath the mucous membrane, on the walls and 
septa of the air-cells, and upon the walls of the intercellu- 
lar passages. The arrangement in these capillaries is such 
that the blood is exposed on all sides to the action of the 
air. 



100 A COMPEND OF 

The Bronchial Arteries supply blood for the nutrition 
of the lung: they are derived from the thoracic aorta, and 
accompanying the bronchial tubes, are distributed to the 
bronchial glands and upon the walls of the larger bron- 
chial tubes and pulmonary vessels, and terminate in the 
deep bronchial veins. Others are distributed in the inter- 
lobular areolar tissue, and terminate partly in the deep, 
partly in the superficial, bronchial veins. Lastly, some 
ramify upon the walls of the smallest bronchial tubes, and 
terminate in the pulmonary veins. 

The Superficial and Deep Bronchial Veins unite at the 
root of the lung, and terminate on the right side in the 
vena azygos (XVI.. 20) ; on the left, in the superior inter- 
costal vein (2.3). 

The Lymphatics consist of a superficial and a deep set; 
they terminate at the root of the lung, in the bronchial 
glands. 

Nerves. The lungs are supplied from the anterior and 
posterior pulmonary plexuses, formed chiefly by branches 
from the sympathetic and pneumogastric. The filaments 
from these plexuses accompany the bronchial tubes, upon 
which they are lost. Small ganglia are found upon these 
nerves. 

THYKOID GLAND, 

(X., n.) 

The Thyroid Gland bears much resemblance in struc- 
ture to other glandular organs, and is usually classified, to- 
gether with the thymus, suprarenal capsules, and spleen, 
under the head of ductless glands, since it has no excretory 



ANATOMY AND PHYSIOLOGY. IOI 

duct. Its function is unknown, but from its situation in 
connection with the trachea and larynx, the thyroid body 
is usually described with those organs, although it is not 
known to take any part in the function of respiration. It 
is situated at the upper part of the trachea, and consists 
of two lateral lobes, placed one on each side of that tube, 
and connected together by a narrow transverse portion, 
the isthmus. It occasionally becomes enormously hyper- 
trophied, constituting the disease called bronchocele, or 
goitre. 

Vessels and Nerves. The arteries supplying the thyroid 
are the superior and inferior thyroid, and sometimes an 
additional branch from the arteria innominata, or the arch 
of the aorta, which ascends on the front of the trachea. 
These are remarkable for their large size and frequent an- 
astomoses. 

The veins form a plexus on the surface of the gland and 
on the front of the trachea, from which arise the superior, 
middle, and inferior thyroid veins; the former terminating 
in the internal jugular, the latter in the vena innominata. 
The lymphatics are numerous, of large size, and terminate 
in the thoracic and right lymphatic ducts. The nerves 
are derived from the pneumogastric, and from the middle 
and inferior cervical ganglia of the sympathetic. 

THYMUS GLAND. 



The Thymus Gland presents much resemblance in struc- 
ture to other glandular organs, and is another of the 
organs denominated ductless glands. This gland is a 



* 



102 A COMPEND OF 

temporary organ, attaining its full size at the end of the 
second year, when it ceases to grow, and gradually dwindles 
until, at puberty, it has almost disappeared. When its 
growth is most active it consists of two lateral lobes, placed 
in close contact along the middle line, situated partly in 
the anterior mediastinum, partly in the neck, and extend- 
ing from the fourth costal cartilage upward, as high as the 
lower border of the thyroid gland. It is covered by the 
sternum and by the origins of the sterno-hyoid and 
sterno-thyroid muscles. In the mediastinum it rests upon 
the pericardium, being separated from the arch of the aorta 
and great vessels by the thoracic fascia. In the neck it 
lies on the front and sides of the trachea, behind the sterno- 
hyoid and sterno-thyroid muscles. It is about two inches 
in length and one and a half in breadth. 

Movements of Respiration. The air in the pulmonary 
lobules and vesicles, being used for the arterialization of 
the blood, is rapidly altered in composition, and requires 
to be replaced by a fresh supply. Its renewal is effected 
by alternate movements of expansion and collapse of the 
chest, following each other in regular succession, known 
respectively as the " movement of inspiration" and the 
" movement of expiration." 

The movement of inspiration is effected by the inter- 
costal muscles drawing the ribs and sternum upward and 
outward, and the diaphragm contracting its fibres in such 
manner that both the upper and lower dimensions of the 
thoracic cavity are increased, so that the air forces its way 
through the trachea and bronchi into the lungs. 

In certain abnormal conditions the activity of either the 



ANATOMY AND PHYSIOLOGY. 103 

intercostal muscles or the diaphragm may be separately 
suspended, leaving the work of respiration to be per- 
formed by the remaining set of musqles. If the intercostals 
be paralyzed by injury of the spinal cord in the lower cer- 
vical or upper dorsal region, the thorax remains quiescent, 
while the protrusion of the abdomen is increased to a cor- 
responding degree. This mode of breathing is called ab- 
dominal respiration. 

In cases of peritonitis, on the other hand, the movements 
of the diaphragm are restrained, owing to the tenderness 
of the inflamed surface. This is called thoracic respira- 
tion. 

The movement of expiration is accomplished by the re- 
laxation of the diaphragm and intercostal muscles, so that 
the pulmonary cavity is partially emptied, mainly by the 
elastic reaction of the lung tissue, which compresses the 
pulmonary lobules and vesicles and expels a portion of 
the contained air. By the recurrence of these two move- 
ments of inspiration and expiration, fresh portions of air 
are alternately introduced into and expelled from the pul- 
monary cavity. 

All the air in the lungs, however, is not changed at each 
movement. A considerable quantity remains behind after 
the most complete expiration; and even when the lungs 
have been removed from the chest, they still contain a cer- 
tain volume of air, which cannot be displaced by any vio- 
lence short of disintegrating the pulmonary tissue. Only 
a comparatively small portion of the air, therefore, passes 
in and out with each respiratory movement, and its com- 
plete renewal will require several successive respirations. 



104 A COMPEND OF 

Eight or ten respirations would be necessary to entirety 
renovate the air in the lungs. 

Movements of the Glottis. Besides the movements of res- 
toration belonging to the chest, there are similar changes 
of expansion and collapse in the larynx. If the respiratory 
passages be examined after death, the opening of the glot- 
tis will be found smaller than the cavity of the trachea. 
The air-passage at the level of the glottis is a narrow 
chink, but it widens considerably in the lower ,part of the 
larynx, while the trachea is a spacious cylindrical tube. 
The space between the vocal chords has an area, on the 
average, of only 0.16 of an inch; while the calibre of the 
trachea in the middle of its length is 0.449b" of an inch. 
But this disproportion does not exist during life. In res- 
piration there is a regular movement of the vocal cords 
synchronous with that of the chest, by which the size of 
the glottis is alternately enlarged and diminished. At in- 
spiration the glottis opens, admitting the air freely into the 
trachea; at expiration it collapses as the air is expelled 
from below. These movements are the " respiratory move- 
ments of the glottis." They correspond in every respect 
with those of the chesty and are excited or retarded by 
similar causes. When the general movements of respira- 
tion are hurried, those of the glottis are also accelerated, 
and when the movements of the chest are slower or fainter 
than usual, those of the glottis are diminished in the same 
proportion. 

The movements of respiration follow each other for the 
most part with great regularity, and, according to the most 
extensive and varied observations, at the average rate of 



ANATOMY AND PHYSIOLOGY. 105 

20 inspirations per minute. This varies under different 
conditions, one of the most important of which is age. As a 
rule, respiration is more rapid in children than in adults. 

The movements of respiration are involuntary in char- 
acter, and even their acceleration or diminution is mainly 
regulated by influences beyond our control. It is possible 
for a short time to increase or retard the rate of respiration 
within certain limits by voluntary effort, but this cannot 
be done continuously. 

CHANGES IN THE AIE BY .RESPIRATION. 

The atmospheric air is a mixture of oxygen and nitrogen 
in the proportion, by volume, of about 21 parts of oxygen 
to 79 parts of nitrogen. It also contains 0.05 per cent of 
carbonic acid, a varying quantity of watery vapor, and 
some traces of ammonia. The last-named ingredients, so 
far as animal respiration is concerned, are insignificant in 
comparison with the oxygen and nitrogen, which form the 
principal part of its mass. 

As discharged from the lungs in expiration, the air is 
found to have become altered in the following particulars : 
first, it has lost oxygen; secondly, it has gained carbonic 
acid; and, thirdly, it has absorbed the vapor of water. The 
most important of these changes are its diminution in 
oxygen and its increase in carbonic acid. The air loses 
during respiration, on an average, five per cent of its 
volume of oxygen. At each inspiration about one cubic 
inch of oxygen is removed from the air and absorbed by 
the blood. 



106 A COMPEND OF 

Owing to its diminution in oxygen, air which has once 
been breathed is less capable of supporting respiration 
than before. When the operation is confined within a 
limited space, the air becomes poorer in oxygen as respira- 
tion goes on, and when its proportion has been reduced to 
a certain point, death ensues, because a substance essential 
to life is no longer present in sufficient quantity. 

The expired air usually contains about four per cent of 
its volume of carbonic acid which it has absorbed in the 
lungs. Bather less than 0.75 of a cubic inch of this gas is, 
therefore, given off with each ordinary expiration. The 
discharge of carbonic acid is not altogether confined to 
the lungs, but takes place also, in some measure, by the 
action of the kidneys and the perspiration. In regard to 
the exhalation by the skin, it has been found, by inclosing 
one of the limbs in an air-tight case, that the air in which 
it is confined loses oxygen and gains carbonic acid. It is 
estimated that the carbonic acid given off from the whole 
cutaneous surface in man is from one-sixtieth to one- 
thirtieth of that discharged by the lungs. 

Notwithstanding the abundance of free nitrogen in the 
atmosphere and its existence to some extent in the cir- 
culating fluids, this substance takes no direct part in res- 
piration or nutrition. It appears to serve as a vehicle or 
medium of admixture for the introduction of oxygen, re- 
maining in other respects an indifferent substance in the 
respiratory process. 

The water exhaled with the breath is given off by the 
pulmonary mucous membrane, by which it is absorbed from 
the blood. At ordinary temperatures it is an invisible 



ANATOMY AND PHYSIOLOGY. IO7 

vapor; but in cold weather it becomes partly condensed on 
leaving the lungs and appears as a cloudy precipitate in 
the breath. The averge quantity exhaled from the lungs 
is about 0.1 pound per day. 

Besides carbonic acid and water, the expired air contains 
an organic ingredient which communicates a faint but 
perceptible odor to the breath. This substance is dis- 
charged as an ingredient in the watery vapor of respiration. 
Under ordinary circumstances it is in so small quantity as 
to be hardly noticeable; but if a large number of persons 
remain for some hours in an apartment with insufficient 
ventilation, it accumulates in the atmosphere to such an 
extent that its odor becomes offensive. 

When fresh and in the healthy condition, the organic 
ingredient of the expired breath is not offensive, and ap- 
pears to have no unwholesome qualities. It is only when 
accumulated in undue quantity and allowed to stagnate in 
the atmosphere that its disagreeable properties become 
manifest. The effect of carbonic acid as produced by res- 
piration cannot be ascertained by that of carbonic acid 
alone. A man or an animal suddenly introduced into an 
atmosphere of pure carbonic acid dies at once by suffoca- 
tion. But this result is not caused by the influence of car- 
bonic acid. It is due to the absence of oxygen, and death 
would take place as promptly in an atmosphere of nitrogen 
or any other indifferent gas. Pure carbonic acid mixed 
with atmospheric air of normal constitution is not so fatal 
in its effect as sometimes represented. A mixture of car- 
bonic acid and atmospheric air in equal volumes produces 
a perceptible feeling of warmth and pungency at the glot- 



I08 A COMPEND OF 

tis, but may still be readily drawn into the lungs. After 
two or three deep inspirations, the strong sense of want of 
air, with rapid and laborious respiration, comes on as before. 
The dyspnoea, suffusion of face, and lividity are less marked 
than after breathing the pure gas, but the subsequent con- 
dition of quiescence and partial anaesthesia is more decided 
and of longer continuance. 

A. mixture of one volume of carbonic acid with three 
volumes of atmospheric air may be inspired without diffi- 
culty, producing a rather agreeable sensation in the lungs. 

Pure nitrogen has no taste nor odor, nor does it have 
any stimulating effect on the mucous membrane. It may 
be inspired to the amount of 366 cubic inches without 
producing any sense of dyspnoea or any perceptible effect 
on the nervous system. 

All the causes of vitiation of the air in respiration, not- 
withstanding the differences in their nature and effects, 
are to be obviated by the same means; that is, a sufficient 
renewal of the- air by ventilation. 

It has been seen that in man, with each respiration, on 
the average, one cubic inch of oxygen is absorbed, and 
about four-fifths of a cubic inch of carbonic acid given off. 
As the oxygen thus taken in weighs rather less than 0.8 of 
an ounce, while the carbonic acid discharged weighs 0.88 
of an ounce, it is evident that the gross result is a loss of 
weight to the system, and this loss, by continued respira- 
tion, amounts on the average to a little over 2.464 ounces 
per day. This is one of the most important facts connected 
with respiration. It shows that this function is carried on 
at the expense of the bodily substance, since the oxygen 



ANATOMY AND PHYSIOLOGY. ICX) 

and carbon discharged under the form of carbonic acid 
weighs more than the oxygen absorbed in a free state. The 
difference must, therefore, be supplied in some way by the 
food; and if this be withheld, respiration alone will be suffi- 
cient to diminish gradually the weight of the body and to 
bring it at last to a state of emaciation. 

CHANGES IN THE BLOOD BY EESPIEATION. 

The blood as it circulates in the arterial system has a 
bright scarlet color, but in passing through the capillaries 
it gradually becomes darker, and on arriving in the veins 
it is deep purple, or in some situations nearly black. There 
are, therefore, two kinds of blood in the body: arterial 
blood, which is of a bright color, and venous blood, which 
is dark. The dark-colored venous blood is incapable in 
this state of supplying the organs with their normal stim- 
ulus and nutrition, and has thus far lost its value as a cir- 
culating fluid. It is accordingly returned to the heart by 
the veins, and is then sent, through the pulmonary artery, 
to the lungs. In passing through the pulmonary circula- 
tion it reassumes its scarlet hue and is again converted into 
arterial blood. Thus the most striking physical effect pro- 
duced in the blood by respiration is its change of color 
from venous to arterial. This change is effected by the air 
in the pulmonary cavities. 

Passage of Oxygen ikto the Blood. — The oxygen 
which disappears from the air in the lungs is taken up by 
the blood in the pulmonary capillaries. It does not enter 
into immediate chemical union with the organic ingredi- 



110 A COMPEND OF 

ents present, but remains in such loose combination tbat 
it may be removed from the blood by the air-pump or by 
a current of hydrogen or nitrogen, and especially by the 
action of carbonic oxide, which expels it completely. Its 
quantity in the arterial blood may vary from a little over 
10 per cent to 22 per cent by volume; the average being 
about 15 per cent. Nearly the whole of the oxygen thus 
taken up is absorbed by the red globules, which have a 
special capacity in this respect. This is shown by the fact 
that the absorbent capacity of the blood for oxygen depends 
on the presence or absence of the red globules. 

It is the oxygen that gives the blood its red color inde- 
pendent of the carbonic acid. It is taken up by the blood- 
globules and changes their color from dark purple to bright 
red. It passes off with the arterial blood in this condition, 
and is then distributed to the capillary circulation. Here, 
as the blood comes in contact with the tissues, its oxygen 
in great 'measure disappears, and its color is again changed 
from arterial to venous. 

The loss of oxygen in the capillaries Of the general cir- 
culation is due to its transfer from the blood-globlues to 
the tissues. Nearly all the tissues exert an absorbent power 
upon oxygen when exposed to this gas or to atmospheric 
air. Experiments have shown that the fresh tissues, taken 
from the body and exposed to the air in closed vessels, ab- 
sorb oxygen with different degrees of intensity in the fol- 
lowing order, namely : muscles, brain, kidneys, spleen, and 
pounded bones. Of these the muscles are the most active 
and the bones the least so, the difference being as 50 to 
17. The absorbent capacity of the tissues for oxygen is 



ANATOMY AND PHYSIOLOGY. Ill 

even greater than that of the blood. Thus the blood- 
globules serve as carriers of oxygen from the lungs, where 
it is absorbed, to the tissues, where it is consumed; the first 
object of respiration being to supply oxygen to the blood, 
in order that the blood may supply it to the tissues. 

EXHALATION OP CARBONIC ACID BY THE 
BLOOD. 

The venous blood, as it returns to the heart, is charged 
with carbonic acid to such an extent that a portion of this 
gas is exhaled through the pulmonary membrane and dis- 
charged with the breath. Its quantity in the blood has 
not been determined with the same accuracy as that of 
oxygen. We know that on the average 0.8 of a cubic inch 
of carbonic acid is discharged from the lungs with each 
expiration, and during this interval, judging from the ca- 
pacity of the heart and its frequency of pulsation, there 
can hardly be less than 24 cubic inches of blood passing 
through the pulmonary circulation. This would give only 
a little over three per cent as the volume of carbonic acid 
discharged from a given quantity of blood in respiration. 

Unlike oxygen, the carbonic acid of the blood is princi- 
pally contained in the plasma and not in the globules; 
since the serum has nearly the same capacity of absorption 
for this gas as the entire blood. 

The source of the carbonic acid of the blood, as well as 
the destination of its oxygen, is in the tissues. Every or- 
ganized tissue in the recent condition has the power both 
of absorbing oxygen and of exhaling carbonic acid. It is 



%12 A COMPEND OF 

in their substance, accordingly, that the oxygen is con- 
sumed and the carbonic acid takes its origin. The precise 
mode in which carbonic acid originates in the solid organs 
is unknown, but is probably by some decomposition in which 
a portion of the carbon and oxygen separate from their 
previous combinations in this form, while the remaining 
elements unite to produce other substances of different 
composition. The most palpable phenomena of respiration 
consist, accordingly, in an interchange of gases between 
the blood and the lungs. As the blood on its return to the 
lungs is comparatively poor in oxygen and abundant in 
carbonic acid, it absorbs the former gas from the pulmo- 
nary cavity and discharges the latter with the expired air. 
These changes, however, are incomplete, both in the air 
and in the blood. The expired air has never lost the whole 
of its oxygen, and it contains only about four per cent of 
carbonic acid. On the other hand, venous blood still con- 
tains a moderate percentage of oxygen, and a certain 
quantity of carbonic acid is also present in arterial blood. 
It is only the proportion of these gases which is changed 
in respiration, the carbonic acid of the blood being dimin- 
ished and its oxygen increased during its passage through 
the lungs. The office of the respiratory apparatus is to 
afford ingress and egress to oxygen and carbonic acid, two 
substances which enter and leave the body in the gaseous 
form, but which have no immediate relation with each 
other, excepting that they are absorbed and exhaled by the 
same organs. They represent the beginning and the end 
of a series of internal changes which are among the most 
important of those connected with the maintenance of life. 



ANATOMY AND PHYSIOLOGY. II3 



ORGANS OF THE CIRCULATION OF THE 
BLOOD. 

The circulatory system is an apparatus by which the 
blood is transported to different regions of the body, and 
by which, after serving for nutrition, absorption, or secre- 
tion, it is returned to the lungs for aeration. By this 
movement of the blood in a continuous circuit, the ma- 
terials absorbed in the alimentary canal are conveyed to 
distant parts for their nourishment and growth, the oxygen 
taken in by the lungs is distributed throughout the body, 
the products of excretion find their way to the outlets of 
the system, and the losses by exhalation in one organ are 
made good by absorption in another. The mechanical 
function by which this is accomplished is regulated by the 
conditions of compression, fluidity, and resistance under 
which the blood moves through the blood-vessels. 

The circulatory apparatus consists of four different parts, 
namely: 1st. The Heart, a hollow muscular organ which 
propels the blood. 2d. The arteries, a series of branching 
tubes which convey it to different parts of the body. 3d. 
The capillaries, a network of inosculating tubules, inter- 
woven with the substance of the tissues, bringing the blood 
into intimate relation with their component parts. 4th. 
The veins, a system of converging vessels which collect 
the blood from the capillaries and return it to the heart. 
In each of these different parts of the circulatory appa- 
ratus the movement of the blood is dependent on special 
conditions. 
8 



114 A COMPEND OF 

THE HEART. 
(X., 6; XII, LXXXIX, XC, XCI.) 

The structure of the heart and its relation with the ad- 
jacent vessels is particularly connected with the activity 
and mechanism of respiration. In man this function is 
very active, and is performed almost exclusively by the 
lungs. The whole of the blood, accordingly, after return- 
ing from the periphery, passes through the lungs before it 
is again distributed to the system at large. It thus trav- 
erses in succession the general circulation of the whole 
body and the special circulation of the lungs. The heart 
consists of a right auricle (XC, 3) and ventricle (4), receiv- 
ing the blood from the vena cava (1) and driving it to the 
lungs, and a left auricle (7) and ventricle (8), receiving the 
blood from the lungs and propelling it outward through 
the arterial system. 

It is therefore a double organ with two sets of muscular 
cavities, right and left; its right cavities being devoted to 
the circulation through the lungs, its left cavities to that 
through the general system. It is of a somewhat conical 
form; its base, situated upon the median line, being di- 
rected upward and backward, while its apex points down- 
ward and forward and to the left, surrounded by the peri- 
cardium, but capable of a certain degree of lateral and 
rotary motion. The auricles, which have a smaller capacity 
and thinner walls than the ventricles, are situated at its 
upper and posterior part, while the ventricles occupy its 
anterior and lower portions. The two ventricles, moreover, 



ANATOMY AND PHYSIOLOGY. 11$ 

are njioii different planes. The right ventricle is some- 
what in front and above the left ; *so that in an anterior 
view the greater portion of the left ventricle is concealed 
by the right, and in a posterior view the greater portion of 
the right ventricle is concealed by the left; while in both 
positions the apex of the heart is constituted altogether by 
the point of the left ventricle. 

The cavities of the heart and of the adjacent blood- 
vessels on each side, though continuous with each other, 
are partially separated by certain constrictions. The 
orifices by which they communicate are known by the 
names of the auricular, auriculo-ventricular, and aortic and 
pulmonary orifices; the auricular orifices being the pas- 
sages from the venae cavae and pulmonary veins into the 
right and left auricles; the auriculo-ventricular orifices 
leading from the auricles into the ventricles, and the aortic 
and pulmonary orifices leading from the ventricles into the 
aorta and pulmonary artery respectively. 

The auriculo-ventricular (XCL, 1, 2), aortic (3), and 
pulmonary orifices (4) are furnished with valves, which 
allow the blood to pass from the auricles to the ventricles 
and from the ventricles to the arteries, but close against its 
return in the opposite direction. The course of the blood 
through the heart is therefore as follows : From the vena 
cava (XII., 14, 16) into the right auricle (2), and from the 
right auricle into the right ventricle (3). On the contrac- 
tion of the right ventricle the tricuspid valves shut back, 
preventing its return into the auricle, and it is driven 
through the pulmonary artery (11) to the lungs. Return- 
ing from the lungs, it enters the left auricle (4), thence 



Il6 A COMPEND OF 

passes into the left ventricle (5), from which it is delivered 
into the aorta (6) and distributed throughout the body. 
The two streams of blood, arterial and venous, in their pas- 
sage through the heart, follow, in each case, a curvilinear 
and more or less spiral direction, the axis of the currents 
crossing each other in the right and left cavities respectively. 
The venous blood, received by the right auricle from the 
vena cava, passes downward and forward into the ventricle. 
It there turns from below upward, from right to left and 
from before backward, through the conus arteriosus, to 
the pulmonary artery. On returning from the lungs to the 
left auricle, it passes downward into the left ventricle, 
when it makes a turn like that upon the right side, pass- 
ing from below upward and from left to right, behind the 
conus arteriosus, and crossing its axis at an acute angle to 
the commencement of the aorta. The aorta, though at its 
origin somewhat posterior to the pulmonary artery, soon 
comes to the front in its arched portion, while the pulmo- 
nary artery runs almost directly backward. Thus the two 
blood-currents twist spirally round each other in their 
course. 

The passage of the blood through the heart is accom- 
plished by alternate contraction and relaxation of its mus- 
cular walls; by which successive portions are delivered 
from the auricles into the ventricles and thence into the 
arteries. Each movement of this kind is called a beat or 
pulsation of the heart. The cardiac pulsations are ac- 
companied by certain phenomena dependent on the struc- 
ture of the organ and its mode of action. 

The position of the heart in the chest may be described 



ANATOMY AND PHYSIOLOGY. 117 

as follows (XL, immediately below X., but not marked on 
the manikin) : 

It is placed obliquely in the chest; the broad attached 
end or base corresponds to the interval between the fifth 
and eighth dorsal vertebrae; the apex corresponds to the 
interspace between the cartilage of the fifth and sixth 
ribs, one inch to the inner side and two inches below the 
nipple. The heart is placed behind the lower two-thirds 
of the sternum, and projects further into the left than into 
the right cavity of the chest, extending from the median 
line about three inches in the former direction, and only 
one and a half in the latter. Its upper border would cor- 
respond to a line drawn across the sternum on a level with 
the upper border of the third costal cartilages; and its 
lower border to a line drawn across the gladiolus from the 
costo-xiphoid articulation of the right side to the point 
above mentioned as the situation of the apex. The lung 
covers a part of the heart, and during inspiration, when 
their borders nearly meet behind the sternum, a thin layer 
of lung covers the roots of all the large vessels. 

The heart in the adult measures about five inches in 
length, three inches and a half in breadth in the broadest 
part, and two inches and a half in thickness. It varies 
in weight from eight to twelve ounces, and continues 
to increase in size and weight to an advanced period 
of life; this increase is more marked in men than in 
women. 

The Valves of the Heakt. — The openings into the 
right auricle from the superior vena cava and those into 



Il8 A COMPEND OF 

the left auricle from the right and left pulmonary veins 
are not provided with valves.* 

The right auriculo-ventricular orifice is guarded by 
the tricuspid valve (XCL, 1). The pulmonary artery is 
guarded by the pulmonary semilunar valves (4). The left 
auriculo-ventricular orifice is guarded by the mitral valve 
(2), and the aortic opening is guarded by semilunar 
valves (3). 

THE PERICARDIUM. 

The Pericardium is a conical membranous sac in which 
the heart and the commencement of the great vessels are 
contained. It is placed behind the sternum and the carti- 
lages of the third, fourth, fifth, sixth, and seventh ribs of 
the left side, in the intervals between the pleurae. 

Its apex is directed upward and surrounds the great vessels 
about two inches above their origin from the base of the 
heart. Its base is attached to the central tendon of the 
diaphragm, extending a little further to the left than to 
the right side. In front it is separated from the sternum 
by the remains of the thymus gland above and a little loose 
areolar tissue below, and is covered by the margins of the 
lungs, especially the left. Behind it rests upon the bron- 
chi, the oesophagus, and the descending aorta. Laterally 
it is covered by the pleura, the phrenic vessels and nerve 
descending between the two membranes on either side. 

The pericardium is a fibro-serous membrane, and con- 



* The Eustachian valve is at the opening* of the inferior vena 
cav^ 



ANATOMY AND PHYSIOLOGY. I IQ 

sists, therefore, of two layers : an external fibrous and an 
internal serous. 



THE ABTEEIAL CIRCULATION. 

The arteries are a system of branching tubes which com- 
mence with the aorta and ramify throughout the body, dis- 
tributing the blood to the peripheral vascular organs. 
They consist of three principal coats, namely : an inner 
coat composed of thin elastic laminae lined with flattened 
epithelium cells; a middle coat containing elastic tissue 
and unstriped muscular fibres, arranged transversely 
around the vessel ; and an external coat of condensed con- 
nective tissue. The principal difference between the 
larger and smaller arteries is in the structure of their 
middle coat. In the smaller arteries this is composed ex- 
clusively of muscular fibres. In arteries of medium size it 
contains both muscular and elastic tissue; while in those 
of the largest calibre it consists of elastic tissue alone. The 
large arteries, accordingly, have much elasticity and but 
little contractility; while the smaller are contractile and 
less elastic. 

The movement of the blood in the arteries is clue to the 
impulse of the ventricular systole. The arterial system 
may be regarded as a great vascular cavity, subdivided by 
the successive branching of its vessels, but communicating 
freely with the heart at one extremity and with the capil- 
lary plexus at the other. At the time of the heart's con- 
traction the muscular walls of the ventricle close upon its 
contents, and as the auriculo-ventricular valves shut back 



120 A COMPEND OF 

and prevent regurgitation, the blood is forced out from the 
ventricle through its arterial orifice. Under these recurring 
impulses the blood moves from the heart through the ar- 
terial system. 

Arterial Pulse. — At each ventricular systole a charge of 
blood is driven into the arteries, distending them by the 
additional fluid forced into their cavities. When the ven- 
tricle relaxes, its distending force is suspended, and the 
elastic arterial walls, reacting upon their contents, would 
drive the blood back into the heart were it not for the 
closure of the semilunar valves, which prevent a backward 
movement. The blood is accordingly propelled, under the 
elastic pressure of the arterial walls, into the capillary 
system. When the arteries, thus partially emptied, have 
returned to their previous dimensions, they are again 
distended by another contraction of the heart. This 
produces, throughout the arterial system, a succession of 
expansions and reactions, known as the arterial pulse. 

Since each arterial expansion is produced by a ventricu- 
lar systole, the pulse, as felt in any superficial artery, is a 
convenient guide tor ascertaining the character of the 
heart's action. The radial artery at the wrist, owing to its 
accessible situation, is usually employed for this purpose. 
Any variation in the frequency, force, or regularity of the 
heart's movement is indicated by a corresponding modifi- 
cation of the pulse of the wrist. The average frequency 
of the pulse in man is, for the adult male in a state of 
quiescence, 70 beats per minute. This rate may be accel- 
erated by muscular action. Even the variation of mus- 
cular effort between the standing, sitting, and recumbent 



ANATOMY AND PHYSIOLOGY. 121 

postures will make a difference in frequency of the pulse 
of from 8 to 10 beats per minute. Age has a marked in- 
fluence in the same direction. 

As a rule, the rapidity of the heart's action is in inverse 
ratio to its force. A slow pulse, within physiological limits, 
is usually a strong one, and a rapid pulse comparatively 
feeble. This is true in disturbance of the heart's action 
from morbid causes; the pulse in febrile or other debili- 
tating affection becoming weaker as it grows more rapid. 
An excessive rapidity of the pulse is an indication of great 
danger, and in the adult male a continued rate of 160 per 
minute is almost invariably a fatal symptom. 

By reason of the distention of the arteries under the 
force of the ventricular systole, these vessels are elongated 
as well as widened, and by this means there is an increase 
of their curvatures at every pulsation. This is apparent, 
in persons that become emaciated, where the arteries come 
to the surface. This increase in size and curvature be- 
comes permanent as age advances. 

The shock of an arterial pulsation, as perceived by the 
finger, varies a little in time, according to its distance 
from the centre of circulation. If one finger be placed 
upon the chest over the heart's apex, another over the 
carotid artery at the middle of the neck, little or no differ- 
ence in time is perceptible between the two impulses; the 
distention of the carotid being sensibly simultaneous with 
the heart's contraction. But if the second finger be placed 
on the temporal artery, its impulse is felt to be a little later 
than that of the heart. The pulse of the radial artery at 
the wrist is also later than that of the carotid, and that of 



122 A COMPEND OF 

the posterior tibial at the ankle later than that of the 
radial. The greater the distance from the heart, the later 
the pulsation of the artery. 

But this difference in time of the arterial pulsations in 
different parts of the body is rather relative than absolute. 
The cardiac impulse is communicated at the same instant 
in every part of the arterial system, and the distention be- 
gins in all the arteries simultaneously, but it reaches its 
completion more rapidly in the neighborhood of the heart, 
more slowly at a distance. The pulse, as perceived by the 
finger, marks the condition of maximum distention; and 
this condition occurs at a later period according to the dis- 
tance of the artery from the heart. 

THE AETEKIES. 

(XII.) 

When the venous blood has passed from the right auricle 
(2) into the right ventricle (3), it then passes through the 
pulmonary semilunar valve into the Pulmonary Artery 
(11), which arises from the right ventricle and carries the 
venous blood directly into the lungs, whence it is returned 
by the pulmonary veins (12), having now become arterial, 
into the left auricle (4). This constitutes the lesser or pul- 
monic circulation. The great artery which arises from the 
left ventricle, the aorta (6), conveys arterial blood to the 
body generally, whence it is brought back to the right side 
of the heart, having become venous blood, by means of the 
veins. This constitutes the greater or systemic circula- 
tion. 



ANATOMY AND PHYSIOLOGY. 123 

The distribution of the systemic arteries is like a highly- 
ramified tree, the common trunk of which, formed by the 
aorta, commences at the left ventricle of the heart, the 
smallest ramifications corresponding to the outer surface 
of the body and the contained organs. The arteries are 
found in nearly every part of the body, with the exception 
of the hairs, nails, epidermis, cartilages, and cornea; and 
the larger trunks usually occupy the most protected situa- 
tions, running, in the limbs, along the flexor side, where 
they are less exposed to injury. 

The arteries in their distribution communicate freely 
with one another, forming what is called an anastomosis, 
or inosculation; and this communication is very free be- 
tween the large as well as between the small branches. 
The anastomoses between trunks of equal size are found 
where great freedom and activity of the circulation are 
requisite, as in the brain; here the two vertebral arteries 
unite to form the basilar, and the two internal carotid ar- 
teries are connected by a short communicating trunk; it 
is also found in the abdomen, the intestinal arteries having 
very free anastomoses between their larger branches. In 
the limbs the anastomoses are most frequent and of largest 
size around the joints, the branches of an artery above 
freely inosculating with branches from the vessels below; 
these anastomoses are of considerable interest to the sur- 
geon, as it is by their enlargement that a collateral circula- 
tion is established after the application of a ligature to an 
artery for the cure of aneurism. The smaller branches of 
arteries anastomose more frequently than the larger; and 
between the smallest twigs the inosculations become so 



124 A COMPEND OF 

numerous as to constitute a close network that pervades 
nearly every tissue of the body. 

Throughout the body generally the larger arteria] 
branches pursue a perfectly straight course, but in certain 
situations they are tortuous; thus the facial artery in its 
course over the face, and the arteries of the lips, are ex^ 
tremely tortuous in their course, to accommodate them- 
selves to the movements of the parts. Again, the interna] 
carotid and vertebral arteries, previous to their entering 
the cavity of the skull, describe a series of curves which 
are evidently intended to diminish the velocity of the cur- 
rent of blood by increasing the extent of surface over 
which it moves and adding to the amount of impediment 
which is produced by friction. 



THE AORTA. 

(XII., 6; XVI., 25.) 

The aorta commences at the upper part of the left ven- 
tricle, and, after ascending for a short distance, arches 
backward, to the left side, over the root of the left lung, 
descending within the thorax on the left side of the verte- 
bral column, passes through the aortic opening in the dia- 
phragm, and, entering the abdominal cavity, terminates, 
considerably reduced in size, opposite the fourth lumbar 
vertebra, where it divides into the right and left common 
iliac arteries. Hence its division into the arch of the aorta, 
the thoracic aorta, and the abdominal aorta, from the di- 
rection or position of its parts. 



ANATOMY AND PHYSIOLOGY. 1 2$ 

The branches given off from the arch of the aorta are 
five in number: two of small size from the ascending por- 
tion, the right and left coronary, which distribute their 
branches to the substance of the heart, and three of large 
size from the transverse portion, the innominate artery 
(XII. , 10), the left common carotid (7), and the left sub- 
clavian (8). These distribute their branches to the head 
and neck and upper extremities. 

The arteria innominata, the largest of the three, arises 
from the commencement of the transverse portion in front 
of the left carotid,- and, ascending obliquely to the upper 
border of the right sterno-clavicular articulation, divides 
into the right common carotid (9) and right subclavian ar- 
teries (XVII., 65). This vessel is one and a half or two 
inches in length. 

The two common carotid arteries, although occupying 
a nearly similar position in the neck, differ somewhat in 
their relations at their origin. The right carotid, as indi- 
cated above, arises from the arteria innominata, the left 
from the highest part of the arch of the aorta. In the 
neck the two resemble each other so closely that one de- 
scription will apply to both. Each vessel passes obliquely 
upward to a level with the upper border of the thyroid 
cartilage, where it divides into the external and internal 
carotid, to be distributed to the external and internal parts 
of the cranium respectively. The course of the common 
carotid is indicated by a line drawn from the sternal end 
of the clavicle below T to a point midway between the angle 
of the jaw and the mastoid process above. 

At the lower part of the neck the two common carotid 



126 A COMPEND OF 

nrteries are separated from each other by a very small in- 
terval, which contains the trachea; but at the upper part 
the thyroid body, the larynx and pharynx project forward 
bet-ween the two vessels, and give the appearance of their 
being placed further back in that situation. The common 
carotid artery is contained in a sheath derived from the 
deep cervical fascia, which also incloses the internal jugular 
vein and pneumogastric nerve, the vein lying on the outer 
side of the artery and the nerve between the artery and 
vein, on a plane posterior to both. On opening the sheath, 
these three structures are seen to be separated from one 
another, each being inclosed in a separate fibrous invest- 
ment. 

The External Carotid Artery (X., 1) arises opposite 
the upper border of the thyroid cartilage and ascends to 
the space between the neck of the condyle of the lower 
jaw and the external meatus, where it divides into the 
temporal and internal maxillary arteries. It rapidly di- 
minishes in its size in its course up the neck, owing 
to the number and large size of the branches given off 
from it. 

This artery gives off eight branches, as follows : Superior 
Thyroid and branches distributed to the thyroid gland. 
Lingual and branches distributed to the tongue and 
mouth. Facial and branches supply the tonsils, pharynx, 
submaxillary gland and adjacent muscles, and the chiu 
and lips and side of the nose. Occipital sends branches 
to the sides of the neck and back part of the head. Pos- 
terior auricular is distributed mainly to the ear and its 
appendages. Ascending Pharyngeal sends branches to 



ANATOMY AND PHYSIOLOGY. 1 2J 

Recti capitis antici muscles, the sympathetic, hypoglossal, 
and pneumogastric nerves, and the lymphatic glands of the 
neck to the soft palate, Eustachian tube and tonsil; one 
branch enters the cranium with the internal jugular vein, 
and two others pass up within the cranium and are dis- 
tributed to the dura mater. Temporal (X., 11) sends its 
branches upward from its origin in the substance of the 
parotid gland and is distributed over the side of the head 
and face in front of and over the ear. Internal maxillary 
supplies the deep structures of the face; its branches are 
numerous and their subdivisions many, supplying the deep 
structures of the face, both muscular and osseous. 

The Internal Carotid Artery commences at the 
bifurcation of the common carotid, opposite the upper 
border of the thyroid cartilage, and runs perpendicularly 
upward, in front of the transverse processes of the three 
upper cervical vertebrae, to the carotid foramen in the 
petrous portion of the temporal bone. After ascending it 
for a short distance, it passes forward and inward through 
the carotid canal, and, again ascending a little by the side 
of the sella Turcica, curves upward by the anterior clinoid 
process, where it pierces the dura mater and divides into 
its terminal branches. This vessel supplies the anterior 
part of the brain, the eye and its appendages. 

Its branches are, from the Petrous portion, Tympanic ; 
from the Cavernous portion, Anterior Meningeal, Arteriae 
Eeceptaculi, Ophthalmic; from the Cerebral Portion, An- 
terior Cerebral (XL., a), Middle Cerebral (b), Posterior 
Communicating, and Anterior Choroid. 



128 A COMPEND OF 

SUBCLAVIAN ARTERIES. 
(XVII., -65 j XX., 74.) 

The Subclavian Artery on the right side arises from the 
arteria innominata opposite the right sterno-clavicular ar- 
ticulation; on the left side it arises from the arch of the * 
aorta. The first portion on the right side ascends ob- 
liquely outward from the origin of the vessel to the inner 
border of the Scalenus anticus. On the left side it ascends 
vertically to gain the inner border of that muscle. The 
second part passes outward behind the Scalenus anticus, 
and the third part passes from the outer margin of that 
muscle, beneath the clavicle, to the lower border of the 
first rib, where it becomes the axillary artery. 

The branches of the subclavian artery are four in num- 
ber: the vertebral, internal mammary, the thyroid axis, 
and the superior intercostal; the first three from the first 
portion and the remaining one from the second. 

ARTERIES OF THE BASE OE THE BRAIN. 

The Vertebral Artery is generally the first and largest 
branch of the subclavian, and distributes its branches to the 
posterior portions of the base of the brain. It arises from 
the upper and back part of the first portion of the vessel, 
and, passing upward, enters the foramen in the transverse 
process of the sixth cervical vertebra, and ascends through 
the foramina in the transverse processes of all the vertebrae 
above this. Above the upper border of the axis it inclines 



ANATOMY AND PHYSIOLOGY. I2g 

outward and upward to the foramen in the transverse prof- 
ess of the atlas, through which it passes; it then winds 
backward behind its articular process, runs in a deep groove 
on the upper surface of the posterior arch of this bone, 
and, piercing the posterior occipito-atloid ligament and 
dura mater, enters the skull through the foramen magnum. 
It then passes in front of the medulla oblongata, and 
unites with the vessel of the opposite side at the lower 
border of the pons Varolii, to form the basilar artery 
(XL., c). 

It sends off two branches in the neck, the Lateral Spinal 
to the vertebrse and spinal cord and muscular to the deep 
muscles of the neck. Its branches to the base of the 
brain are Posterior Meningeal, Anterior Spinal, Posterior 
Spinal, and Inferior Cerebellar. 

The Inferior Cerebellar artery, the largest branch of the 
vertebral, winds backward round the upper part of the 
medulla oblongata, passing between the origin of the spi- 
nal accessory and pneumogastric nerves, over the resti- 
form body to the under surface of the cerebellum, where 
it divides into two branches : an internal one, which is 
continued backward to the notch between the two hemi- 
spheres of the cerebellum; and an external one, which 
supplies the under surface of the cerebellum as far as its 
outer border, where it anastomoses with the superior cere- 
bellar. Branches from this artery supply the choroid 
plexus of the fourth ventricle. 

The Basilar Artery (XL., c) at the base of the skull is 
a single trunk formed by the junction of the two Vertebral 
arteries (e) ; it extends from the posterior to the anterior 
9 



130 A COMPEND OF 

border of the pons Varolii, where it divides into two ter- 
minal branches, the posterior cerebral arteries (d). Its 
branches are on each side the following: Transverse, 
Anterior Cerebellar, Superior Cerebellar, and Posterior 
Cerebral. 

CEEEBEAL BRANCHES OF THE INTERNAL 
CAROTID ARTERY. 

The arteria cerebralis arises from the internal carotid at 
the inner extremity of the fissure of Sylvius (XL., B)< 
It passes forward in the great longitudinal fissure between 
the two anterior lobes of the brain, being connected soon 
after its origin with the vessel of the opposite side by a 
short anastomosing trunk, called the anterior communi- 
cating. The two anterior cerebral arteries lying side by 
side curve round the anterior border of the corpus cal- 
losum (A), and run along its upper surface to its posterior 
part, where they terminate by anastomosing with the pos- 
terior cerebral arteries. They supply the olfactory and 
optic nerves, the under surface of the anterior lobes, the 
third ventricle, the anterior perforated space, the corpus 
callosum, and the inferior surface of the hemispheres. 
Sometimes these two arteries are united in a single trunk 
soon after their origin and afterward divide and subdivide, 
in which case, of course, the anterior communicating is ab- 
sent. 

The Middle cerebral artery (XL., b), the largest branch 
of the internal carotid, passes obliquely outward along the 
fissure of Sylvius (B), within which it divides into three 



ANATOMY AND PHYSIOLOGY. I3I 

branches : an anterior, which supplies the pia mater, in- 
vesting the surface of the anterior lobe; a posterior, which 
supplies the middle lobe; and a median branch, which sup- 
plies the small lobe at the outer extremity of the Sylvian 
fissure. Near its origin this vessel gives off numerous small 
branches which enter the locus perforatus anticus, to be 
distributed to the corpus striatum. 

The posterior communicating artery arises from the back 
part of the internal carotid, runs directly backward, and 
anastomoses with the posterior cerebral (d). 

The anterior choroid is a small but constant branch 
which arises from the back part of the internal carotid^ 
near the posterior communicating artery. It enters the 
descending horn of the lateral ventricle beneath the edge 
of the middle lobe of the brain. It is distributed to the 
hippocampus major, corpus fimbriatum, and choroid 
plexus. 

Circle of Willis is the name given to the remarkable an- 
astomosis formed in the base of the brain by the junction 
of the branches of the internal carotid and vertebral ar- 
teries. It is by this that the cerebral circulation is equal- 
ized and provision made for effectually carrying it on if 
one or more of the branches are obliterated. The parts of 
the brain included within this arterial circle are the lamina 
cinerea, the commissure of the optic nerves (2), the in- 
fundibulum, the tuber cinereum, the corpora albicantia, 
and the posterior perforated space. 

The Thyroid Axis is a short thick trunk which arises 
from the subclavian close to the inner border of the sca- 
lenus anticus muscle, and divides almost immediately into 



I32 A COMPEND OF 

three branches, the inferior thyroid, supra-scapular, and 
transversalis colli. 

The inferior thyroid passes upward in a serpentine 
course behind the sheath of the common carotid vessel 
and sympathetic nerve, and is distributed to the under sur- 
face of the thyroid gland. Its branches are Laryngeal, dis- 
tributed to the back part of the larynx; Tracheal, to the 
trachea; (Esophageal, to the oesophagus, and Ascending 
cervical, to the vertebral column and the muscles of the 
neck. 

The supra-scapular artery passes obliquely from within 
outward, across the root of the neck, to the superior border 
of the scapula, where it passes over its transverse ligament 
to the supra-spinous fossa. It is mainly distributed to the 
supra-spinatus muscle, and sends branches to other adjacent 
muscles and to the shoulder-joint. 

The transversalis colli passes outward to the anterior 
margin of the trapezius muscle, beneath which it divides 
into two branches, the superficial cervical and the pos- 
terior scapular. The superficial cervical supplies the 
Trapezius and neighboring muscles and glands. The 
posterior scapular sends branches to the Ehomboid, Latis- 
simus dorsi, and Trapezius muscles, anastomosing with the 
subscapular and the posterior branches of some of the in- 
tercostal arteries. 

The Internal Mammary arises from the under surface 
of the subclavian artery (XVII., 65) opposite the thyroid 
axis. It descends behind the clavicle to the inner surface of 
the anterior wall of the chest, resting upon the costal car- 
tilages a short distance from the margin of the sternum 



ANATOMY AND PHYSIOLOGY. 1 33 

(XL, 1), and at the interval between the sixth and seventh 
cartilages divides into two branches, the musculo- phrenic 
and superior epigastric. It is accompanied by two veins 
which join at the upper part of the thorax into a single 
trunk. The branches of this artery are : Superior Phrenic, 
which accompanies the phrenic nerve to the Diaphragm; 
Mediastinal branches, w r hich pass to the Mediastinum and 
the remains of the thymus gland; the pericardiac branches, 
to the pericardium and sternum; the anterior intercostal 
arteries, which inosculate with the intercostal arteries from 
the aorta; the perforating arteries, which supply the mam- 
mary glands; the musculo-phrenic, to the intercostal spaces 
in a similar manner to the other intercostal artery, sending 
some branches to the diaphragm and abdominal muscles; 
and superior epigastric, distributed to the rectus muscle 
and anastomosing wdth the epigastric artery from the ex- 
ternal iliac. 

The superior intercostal artery arises from the upper and 
back part of the subclavian artery, behind the anterior 
scalenus on the right side and to the inner side of the 
muscle on the left. Passing backward it gives off the deep 
cervical branch, and then descends behind the pleura in 
front of the necks of the first two ribs, and inosculates 
with the first aortic intercostal; a branch goes to the pos- 
terior spinal muscles, and another to the spinal cord and 
its membranes. The deep cervical branch passes up the 
neck to the axis, supplying the muscles in its course. 



134 A COMPEND OF 



THE AXILLA AND ITS ARTERY. 

The Axilla is the name given to the space between the 
upper and lateral part of the chest and the inner side of 
the arm. It contains the axillary vessels and brachial 
plexus of nerves, with their branches, some branches of 
the intercostal nerves, and a large number of lymphatic 
glands, all connected together by a quantity of fat and 
loose areolar tissue. 

The Axillary Artery (XVII., 68), the continuation of 
the subclavian, commences at the lower border of the first 
rib and terminates at the lower border of the tendons of 
the Latissimus dorsi and Teres major muscles, where it 
takes the name of brachial. 

The branches of this artery are: Superior thoracic, 
Acromial thoracic, Thoracica longa, Thoracica alaris, 
Subscapular, Anterior circumflex, and Posterior circum- 
flex. These branches are distributed to all the muscles 
and integument of the axilla, from the deltoid and pecto- 
ralis (II., 20, 21) on the front to the tissues covering the 
scapula on the back (L., 7). 

The Brachial Artery (XVII., 69) commences at the 
lower margin of the tendon of the Teres major, and, pass- 
ing down the inner and anterior aspect of the arm, termi- 
nates about half an inch below the bend of the elbow, where 
it divides into the radial and ulnar arteries (70, 71). Oc- 
casionally it is divided into two trunks for a short distance 
at its upper part, which are united above and below. The 
point of bifurcation may be above or below the usual 



ANATOMY AND PHYSIOLOGY. 1 35 

point, the former condition being by far the most fre- 
quent. The divisions of the main arteries in the arm are 
variable in other respects also. 

The branches of the brachial artery are the Superior pro- 
funda, Nutrient artery, Inferior profunda, 'Anastomotica 
magna, and muscular. The most noted of these is the 
Anastomotica magna, by reason of its connection with the 
anastomosis around the elbow-joint. 

The Radial Artery (XVII., 71) commences at the bifur- 
cation of the brachial and passes along the radial side of 
the forearm to the wrist; it then winds back around the 
outer side of the carpus, beneath the extensor tendons of 
the thumb, and finally passes forward between the two 
heads of the first dorsal interosseous muscle into the palm 
of the hand, where it crosses the metacarpal bones to the 
ulnar border of the hand, to form the deep palmar arch 
(XVIIL, 4). At its termination it inosculates with the 
deep branch of the ulnar artery. This artery is accom- 
panied by two venae comites throughout its whole course. 

The branches of the radial are — in the forearm, Radial 
recurrent, Muscular, Superficialis volse, Anterior carpal; 
in the wrist, Posterior carpal, Metacarpal, Dorsales pollicis, 
Dorsales indicis; and in the hand, Princeps pollicis, 
Kadialis indicis, Perforating, and Interosseous. 

The Ulnar Artery (XVII., 70), the larger of the two sub- 
divisions of the brachial, commences a little below the 
bend of the elboAv and crosses the inner side of the forearm 
obliquely inward to the commencement of its lower half; 
it then runs along its ulnar border to the wrist, crosses 
the annular ligament on the radial side of the pisiform 



136 A COMPEND OF 

bone, and passes across the palm of the hand, forming the 
superficial palmar arch (XV1IL, 2), which sometimes ter- 
minates by inosculating with the superficialis volae. 

The branches of the ulnar are — in the forearm, Anterior 
Ulnar Kecurrent, Posterior Ulnar Kecurrent, Interosseous, 
(XVII., 72), and muscular; in the wrist, Anterior carpal 
and Posterior carpal; in the hand, Deep, or communicat- 
ing, and Digital branches (XVIIL, 3). The most im- 
portant are the interosseous with its two branches and 
the digital branches to the fingers arising from the deep 
palmar arch. 

THE DESCENDING AOKTA. 
(XVI., 25.) 

The Descending Aorta is divided into two portions, the 
thoracic and abdominal, in correspondence with the two 
great cavities of the trunk in which it is situated. 

The Thoracic Aorta commences at the lower border of 
the fourth dorsal vertebra on the left side, and terminates . 
at the aortic opening of the Diaphragm in front of the last 
dorsal vertebra. At its commencement it is situated on 
the left side of the spine; it approaches the median line 
as it descends, and at its termination lies directly in front 
of the column. It is contained in the back part of the 
posterior mediastinum. The oesophagus with its accom- 
panying nerves lies on the right side of the aorta above, in 
frout of the artery, in the middle of its course; while at 
its lower part it is on the left side, on a plane anterior 
to it. 



ANATOMY AND PHYSIOLOGY. 1 37 

The brandies of the thoracic aorta are: 

The Pericardiac^ a few small vessels, distributed to the 
pericardium; the Bronchial, two or three in number, dis- 
tributed to the bronchi, the lungs, the bronchial glands, 
and the oesophagus; the oesophageal arteries, four or five 
in number, arising from the front of the aorta, anastomos- 
ing with branches of the inferior tigroid and phrenic and 
gastric arteries to form a chain along the tube ; the Pos- 
terior mediastinal, numerous small vessels supplying the 
glands and loose areolar tissue in the mediastinum, and 
the Intercostal arteries (XVI., 24), arising from the back 
part of the aorta, ten in number on each side, distributed 
to the greater portion of the intercostal spaces, each artery 
dividing in its course into two branches, anterior and pos- 
terior, and each trunk and its branches being accompanied 
by an intercostal nerve and a vein. 

The Abdominal Aorta commences at the aortic opening 
of the Diaphragm, in front of the body of the last dorsal 
vertebra, and descending a little to the left side of the ver- 
tebral column, terminates on the body of the fourth lum- 
bar vertebra, commonly a little to the left of the middle 
line, where it divides into the two common iliac arteries 
(XVI., 52, 53). As it lies upon the bodies of the vertebrae, 
the curve which it describes is convex forward, the great- 
est convexity being in front of the third lumbar vertebra, 
which is a little above and to the left side of the umbilicus. 

The branches of the Abdominal aorta are as follows: 
The Coehc Axis, a short thick trunk, about half an inch in 
length, which arises from the aorta opposite the margin 
of the Diaphragm, and ; passing nearly horizontally for- 



I38 A COMPEND OF 

ward, divides into three large branches, the gastric, hepatic 
(31), and splenic (32), occasionally giving off one of the 
plirenic arteries. The gastric is the principal artery to the 
stomach, some of its branches, however, anastomosing in 
their course with branches from the splenic and hepatic 
arteries. The heptatic is the artery that supplies the liver; 
it sends a pyloric branch to unite with the gastric, the 
Gastro-duodenalis, to distribute branches to the duodenum, 
pylorus, and pancreas, and the cystic artery, which supplies 
the gall-bladder. The Splenic artery is remarkable for 
the tortuosity of its course. It passes horizontally to the 
left side behind the upper border of the pancreas, accom- 
panied by the splenic vein, which lies below it, and on 
arriving near the spleen divides into numerous branches, 
some of which enter the spleen to be distributed to the 
substance of that structure, while others are distributed to 
the great end of the stomach and the pancreas. 

The gastro-epiploica, the largest branch of the splenic, 
anastomosing with a similar branch of the hepatic, runs 
along the great curvature of the stomach, between the 
layers of the great omentum. In its course it distributes 
branches to the stomach which ascend on both surfaces; 
others ascend to supply the omentum. 

The Superior Mesenteric Artery (XVI., 42) supplies the 
whole length of the small intestine except the first part of 
the duodenum; it also supplies the caecum and ascending 
and transverse colon; it is a vessel of large size, arising 
from the fore part of the aorta, about a quarter of an inch 
below the coelic axis, being covered at its origin by the 
s])lenic vein and pancreas. It passes forward between the 



ANATOMY AND PHYSIOLOGY. 1 39 

pancreas and transverse portion of the duodenum, crosses 
in front of this portion of the intestine, and descends be- 
tween the layers of the mesentery to the right iliac fossa, 
where it terminates, considerably diminished in size. In 
its course it forms an arch ; the convexity is directed for- 
ward and downward to the left side, the concavity back- 
ward and upward to the right. It is accompanied by the 
superior mesenteric vein (40) and is surrounded by the 
superior mesenteric plexus of nerves. 

The names of the branches of the superior mesenteric 
artery are the Inferior pancreatico-duodenal, Vasa in- 
testini tenuis, Ileo-colic, Colica dextra, and Colica media. 

By these branches the distribution is made as above in- 
dicated. The distribution of the vasa intestini tenuis, 
twelve or fifteen in number, to the convolutions of the 
jejunum and ileum, is accomplished by an intricate net- 
work or plexus from which minute branches are sent to 
all the parts. 

The Inferior Mesenteric Artery (XVI., 43) supplies the 
descending (XIII., 9) and sigmoid flexure of the colon and 
the greater part of the rectum (10). It arises from the left 
side of the aorta, between one and two inches above its di- 
vision into the common iliacs. It passes downward to the 
left iliac fossa, and then descends between the layers of 
the meso-rectum into the pelvis, under the name of the 
superior hemorrhoidal artery. 

Its branches are the Colica sinistra, Sigmoid, and Su- 
perior hemorrhoidal, by which its distribution is made as 
above indicated. 

The Renal Arteries (XVL, 48, 49) are two large trunks 



140 A COMPEND OF 

which arise from the sides of the aorta immediately below 
the superior mesenteric artery. Each is directed outward 
so as to form nearly a right angle with the aorta. The 
right is longer than the left on account of the position of 
the aorta; it passes behind the vena cava (26). The left 
is somewhat higher than the right. Previously to enter- 
ing the kidney each artery divides into four or five 
branches, which are distributed to its substance. At the 
hilum these branches lie between the renal vein and 
ureter, the vein being usually in front and the ureter be- 
hind. Each vessel gives off some small branches to the 
suprarenal capsules (39), the ureter (44), and the surround- 
ing membrane and muscles. 

The Phrenic Arteries are two small vessels which pre- 
sent much variety in their origin. They may arise sepa- 
rately from the front of the aorta, immediately below the 
coelic axis, or by a common trunk, which may spring either 
from the aorta or the ccelic axis. Sometimes one is de- 
rived from the aorta and the other from one of the renal 
arteries. Their general distribution is to the diaphragm, 
but branches pass also to the inferior vena cava, the 
oesophagus, suprarenal capsules, spleen, and liver. 

The Lumbar Arteries are analogous to the intercostals. 
They are usually four in number on each side and arise 
from the back part of the aorta, nearly at right angles 
with that vessel. They pass outward and backward, 
around the sides of the body of the corresponding lumbar 
vertebra, behind the sympathetic veins and psoas muscle; 
those on the right side being covered by the inferior vena 
cava, and the two upper ones on each side by the crura of 



ANATOMY AND PHYSIOLOGY. I4I 

the Diaphragm. In the interval between the transverse 
processes of the vertebrae each artery divides into a dorsal 
and an abdominal branch. The dorsal branch is distrib- 
uted to the muscles and integument of the back, anasto- 
mosing with each other and with the intercostals; it also 
sends a branch to the spinal canal. 

The abdominal branches pass outward behind the 
Quadratus lumborum muscle, the lowest branch occasion- 
ally in front of that muscle, and being continued between 
the abdominal muscles, anastomose with branches of the 
epigastric and internal mammary in front, the intercostals 
above, and those of the ileo-lumbar and circumflex iliac 
below. 

The Middle Sacral Artery is a small vessel which arises 
from the back part of the aorta, just at its bifurcation. 
It descends upon the last lumbar vertebra and along the 
middle line of the front of the sacrum to the upper part 
of the coccyx, and is distributed to the adjacent parts. 

COMMON ILIAC ARTERIES. 

(XVI., 52, 53.) 

The abdominal aorta divides into the two Common Iliac 
arteries. The bifurcation usually takes place on the left 
side of the body of the fourth lumbar vertebra. This 
point corresponds to the left side of the umbilicus, and is 
on a level w r ith a line drawn from the highest point of 
one iliac crest to the other (XLIIL, 0). They are about 
two inches in length; diverging from the termination of 



142 A COMPEND OF 

the aorta, they pass downward and outward to the margin 
of the pelvis, and divide opposite the intervertebral sub- 
stance, between the last lumbar vertebra and the sacrum, 
into two branches, the external (XVI., 57) and internal 
iliac (56) arteries; the former supplying the lower ex- 
tremity and the latter the viscera and parietes of the pelvis. 
The common iliac arteries give off small branches to the 
peritoneum, psoas muscles, ureters, ami the surrounding 
cellular membrane, and occasionally give origin to the ileo- 
lumbar or renal arteries. 

INTERNAL ILIAC ARTERY. 
(XVI., 56.) 

The Internal Iliac Artery supplies the walls and viscera 
of the pelvis and t inner side of the thigh. It is a short 
thick vessel, smaller than the external iliac, and about an 
inch and a half in length, which arises at the point of 
bifurcation of the common iliac, and passing downward 
to the upper margin of the great sacro-sciatic foramen, 
divides into two large trunks, an anterior and posterior. 

Its anterior trunk has nine branches, its posterior trunk 
has three. 

The Obturator Artery usually arises from the anterior 
trunk of the internal iliac, frequently from the posterior. 
It passes down through the obturator foramen, and divides 
into an external and an internal branch. After sending- 
off a vesical and a pubic branch before leaving the cavity 
of the pelvis, its external branch distributes to the obtura- 
tor, Pectineus, Adductor, and Gracilis muscles. The ex- 



ANATOMY AND PHYSIOLOGY. I43 

ternal branch supplies the Obturator Muscles and sends 
branches to the hip-joint. 

The Sciatic Artery, the larger of the two terminal 
branches of the anterior trunk of the internal iliac, is dis- 
tributed to the muscles on the back of the pelvis. It 
passes down to the lower part of the great sacro-sciatic 
foramen, resting on the sacral plexus of nerves and Pyri- 
formis muscle, and escapes from the pelvis between the 
Pyriformis and Coccygeus. It then descends in the in- 
terval between the trochanter major and tuberosity of the 
ischium, accompanied by the sciatic nerves and covered by 
the Gluteus maximus, and divides into branches which 
supply the deep muscles of the back of the hip. 

The Gluteal Artery is the largest branch of the internal 
iliac, and appears to be the continuation of the posterior 
division of that vessel. It passes out of the pelvis above 
the upper border of the Pyriformis muscle, and immedi- 
ately divides into a superficial and deep branch. Within 
the pelvis it gives off a few muscular branches to the 
Iliacus, Pyriformis, and Obturator interims, and % just pre- 
vious to quitting that cavity a nutrient artery which en- 
ters the ileum. 

EXTEENAL ILIAC AETEEY. 
(XVI., 57.) 

The External Iliac is the chief vessel that supplies the 
lower limb. It passes obliquely downward and outward 
along the inner border of the Psoas muscle, from the bifur- 
cation of the common iliac to the femoral arch, where it 



144 A COMPEND OF 

enters the thigh and becomes the femoral artery. The 
course of this vessel would be indicated by a line drawn 
from the left side of the umbilicus to a point midway be- 
tween the anterior superior spinous process of the ileum 
and the symphysis pubis. Besides several small branches 
to the Psoas muscles and the neighboring lymphatic glands, 
the external iliac gives off two branches of considerable 
size, the Epigastric and Circumflex iliac. 

The Epigastric artery arises from the external iliac a 
little above Poupart's ligament, and after descending to 
that ligament ascends beneath and distributes branches to 
the Pectus muscle, and above the umbilicus anastomoses 
with the internal mammary and intercostal arteries. It is 
accompanied by two veins, which usually unite into a 
single trunk before their termination in the external iliac 
vein. 

The Circumflex Iliac Artery arises from the outer side 
of the external iliac nearly opposite the epigastric, and as- 
cends obliquely outward behind Poupart's ligament, and 
anastomoses with the ileo-lumbar and gluteal arteries. 
This artery also is accompanied by two veins which unite 
in a single trunk which enters the external iliac vein. 

FEMORAL ARTERY. 
1 (XVI., 60; XIX., 1.) 

The Femoral Artery is the continuation of the external 
iliac. It commences immediately behind Poupart's liga- 
ment, midway between the anterior superior spine of the 



ANATOMY AND PHYSIOLOGY. 145 

ilium and the symphysis pubis, and passing down the fore 
part and inner side of the thigh, terminates at the open- 
ing in the Adductor magnus, at the junction of the middle 
with the lower third of the thigh (XIX., 2), where it be- 
comes the popliteal artery. A line drawn from a point mid- 
way between the anterior superior spine of the ilium and 
the symphysis pubis to the inner side of the inner condyle 
of the* femur will be nearly parallel with the course of the 
artery. 

The branches of the femoral artery are the Superficial 
epigastric, Superficial circumflex iliac., Superficial external 
pubic, Profunda femoris, Muscular, and Anastomotica 
magna. 

The Profunda Femoris (XVI., 62) nearly equals in size 
the Femoral, from which it arises. It issues from the outer 
and back part of the femoral artery, one or two inches 
below Poupart's ligament. It at first lies on the outer 
side of the femoral, and then passes behind it and the 
femoral vein to the inner side of the femur, and terminates 
at the lower third of the thigh in a small branch, which 
pierces the Adductor magnus to be distributed to the flexor 
muscles on the back of the thigh, anastomosing with 
branches of the popliteal and inferior perforating arteries 
(XIX., 10). 

The profunda femoris sends out several branches: Ex- 
ternal circumflex, Internal circumflex, and Perforating; 

supplying the anterior and posterior muscles of the thigh. 
10 



I46 A COMPEND OF 

POPLITEAL ARTERY. 

The Popliteal Artery (XIX., 2, 3, 4) commences at the 
termination of the femoral at the opening in the Adductor 
magnus (V., 48), and passing obliquely downward and out- 
ward behind the knee-joint to the lower border of the 
popliteus muscle, divides into the anterior and posterior 
tibial arteries (XXXVII., 2). The region of the limfe trav- 
ersed by this artery is called the Popliteal Space. 

The artery in its course downward to the lower border 
of the popliteus muscle rests first on the inner and then 
on the posterior surface of the femur; in the middle of 
its course, on the posterior ligament of the knee-joint; and 
below, on the fascia covering the popliteus muscle. The 
popliteal vein, which is intimately attached to the artery, 
lies superficial and external to it, until near its termina- 
tion, when it crosses it and lies on its inner side. 

In its course the popliteal artery sends out the following 
branches : 

Superior and Inferior muscular, Cutaneous, External and 
Internal Superior articular, Azygos articular, and External 
and Internal Inferior articular. These distribute filaments 
to the muscles of the popliteal space, to the knee-joint, and 
some to the integument of the calf. 

ANTERIOR TIBIAL ARTERY. 

(XIX, 5.) 

The Anterior Tibial Artery commences at the bifurca- 
tion of the popliteal, at the lower border of the popliteus 
muscle, passes forward between the two heads of the Tibia- 



ANATOMY AND PHYSIOLOGY. 147 

lis posticus, and through the aperture left between the 
bones at the upper part of the interosseous membrane, to 
the deep part of the front of the leg; it then descends 
on the anterior surface of the interosseous membrane and 
of the tibia to the front of the ankle-joint, where it lies 
more superficially and becomes the dorsalis pedis. The 
anterior tibial artery is accompanied by two veins and the 
anterior tibial nerve. The branches of this artery are Re- 
current tibial, Muscular, and Internal and External mal- 
leolar. The two former supply the muscles on the front 
of the leg and the latter the ankle-joint. 

DOESALIS PEDIS ARTERY. 

The Dorsalis Pedis, the continuation of the anterior 
tibial, passes forward from the bend of the ankle along the 
tibial side of the foot to the back part of the first inter- 
osseous space, where it divides into two branches, the dor- 
salis hallucis and communicating. It is accompanied by 
two veins. It has also Tarsal, Metatarsal, and Interosseous 
branches, and all its branches are distributed to the ankle 
and foot, some of them extending to the toes. 

POSTERIOR TIBIAL ARTERY. 
(XIX., 8.) 

The Posterior Tibial is an artery of large size, which ex- 
tends obliquely downward from the lower border of the 
popliteus muscle, along the tibial side of the leg, to the 
fossa between the inner ankle and the heel, where it divides 



I48 A COMPEND OF 

beneath the origin of the Abductor pollicis, into the inter- 
nal and external plantar arteries. At its origin it lies op- 
posite the interval between the tibia and fibula; as it 
descends, it approaches the inner side of the leg, lying 
behind the tibia, and in the lower part of its course is sit- 
uated midway between the inner malleolus and the tuber- 
osity of the os calcis. Its branches are Peroneal, Anterior 
Peroneal, Muscular, Nutrient, Communicating, and Inter- 
nal Calcanean. 

The Peroneal Artery (XIX., 9) lies deeply seated along 
the back part of the fibular side of the leg. It arises from 
the posterior tibial, about an inch below the lower border 
of the Popliteus muscle, passes obliquely outward to the 
fibula, and then descends along the inner border of that 
bone to the lower third of the leg, where it gives ofE the 
anterior peroneal. It then passes across the articulation 
between the tibia and fibula, to the outer side of the os 
calcis, supplying the neighboring muscles and back of the 
ankle, and anastomosing with the external malleolar, tarsal, 
and external plantar arteries. 

The Anterior Peroneal pierces the interosseous mem- 
brane, about two inches above the outer malleolus, to reach 
the fore part of the leg, and passing down beneath the 
Peroneus tertius, to the outer ankle, ramifies on the front 
and outer side of the tarsus, anastomosing with the exter- 
nal malleolar and tarsal arteries. 

The Internal Plantar, one of the terminal branches of 
the posterior tibial artery, arising between the inner ankle 
and the heel, passes forward along the inner side of the 
foot. At the base of the first metatarsal bone, it passes 



ANATOMY AND PHYSIOLOGY. 149 

along the inner border of the great toe, inosculating with 
its digital branches. 

The External Plantar passes obliquely outward and 
forward to the base of the fifth metatarsal bone. It 
then turns obliquely inward to the interval between the 
bases of the first and second metatarsal bones, where it 
anastomoses with the communicating branch from the 
dorsalis pedis artery, thus completing the plantar arch. 

The Plantar Arch (XIX.), besides distributing numer- 
ous branches to the muscles, integument, a'ncl fasciae in the 
sole, gives off the following branches : Posterior perforating, 
and Digital — Anterior perforating, distributing branches 
to the toes. 

OF THE VEINS. 

The Veins are the vessels which serve to return the blood 
from the capillaries of the different parts of the body to 
the heart. They consist of two distinct sets of vessels, 
the pulmonary and systemic. 

The Pulmonary Veins contain arterial blood, which they 
return from the lungs to the left auricle of the heart. 

The Systemic Veins return the venous blood from the 
body generally to the right auricle of the heart. 

The Portal Vein, an appendage of the systemic venous 
system, is confined to the abdominal cavity, returning the 
venous blood from the viscera of digestion, and carrying it 
to the liver to be diffused through this organ and to be trans- 
mitted by the hepatic veins to the vena cava. The veins, like 
the arteries^ are found in nearly every tissue of the body. 



150 A COMPEND OF 

They commence by minute plexuses, which communicate 
with the capillaries. The branches which commence in 
these plexuses unite together into trunks, and these, in 
their passage toward the heart, constantly increase in size 
as they receive branches and join other veins similar in 
size to themselves. The veins are larger and altogether 
more numerous than the arteries; hence the entire capac- 
ity of the venous system is much greater than that of the 
arterial, the pulmonary veins excepted, which do not ex- 
ceed in capacity the pulmonary arteries. In form the 
veins are not perfectly cylindrical like the arteries, their 
walls being collapsed when empty and the uniformity of 
their surface being interrupted at intervals by slight con- 
tractions, which indicate the existence of valves in their 
interior. They usually retain, however, the same calibre as 
long as they receive no branches. 

The veins communicate very freely with each other, es- 
pecially in certain regions of the body; and this communi- 
cation exists between the larger trunks as well as between 
the smaller branches. Thus in the cavity of the cranium 
and between the veins of the neck, where obstruction 
would be attended with imminent danger to the cerebral 
venous system, we find that the sinuses and larger veins 
have large and very frequent anastomoses. The same free 
communication exists between the veins throughout the 
whole extent of the spinal canal, and between the veins 
composing the various venous plexuses in the abdomen 
and pelvis. 

The veins are subdivided inter three sets : superficial, 
deep, and sinuses, 



ANATOMY AND PHYSIOLOGY. I 5 I 

The Superficial or Cutaneous Veins are found between 
the layers of superficial fascia, immediately beneath the 
integument; they return the blood from these structures, 
and communicate with the deep veins by perforating the 
deep fascia. There is a general uniformity in the main 
trunks of these veins, but in the anastomosing and dis- 
tribution of their branches there is great diversity, not 
only in different individuals, but also in the two sides of 
the same individual. 

The Deep Veins accompany the arteries and are usually 
inclosed in the same sheath with them. With the smaller 
arteries, as the radial, ulnar, brachial, tibial, peroneal and 
their subdivisions, they exist generally in pairs, one lying 
on each side of the vessel, and are called venae comites. 
The larger arteries, as the axillary, subclavian, popliteal, 
and femoral, have usually only one accompanying vein. 
In certain organs of the body, however, the deep veins do 
not accompany the arteries ; for instance, the veins in the 
skull and spinal canal, the hepatic veins in the liver, and 
the larger veins returning blood from the osseous tissue. 

Sinuses are venous channels which, in their structure 
and mode of distribution, differ altogether from the veins. 
They are found only on the interior of the skull, and are 
formed by a separation of the layers of the dura mater, 
their outer coat consisting of fibrous tissue, their inner of 
a serous membrane continuous with the serous membrane 
of the veins. 

The veins may be arranged into four groups : 1. Those 
of the head and neck, upper extremity, and thorax, which 
terminate in the superior vena cava (XII., 16). 2. Those 



152 A COMPEND OF 

of the lower limb, pelvis and abdomen which terminate 
in the inferior vena cava (14). 3. The cardiac veins, which 
open directly into the right auricle of the heart (2). 4. 
The pulmonary veins, which open into the left auricle (4). 

VEINS OF THE HEAD AND NECK. 
(XII.) 

The veins of the exterior of the head are Facial (25), 
Temporal (28), Internal maxillary, Temporo-maxillary, 
Posterior auricular, and Occipital (29). The veins of the 
neck are External Jugular (20), Posterior external jugu- 
lar, Anterior jugular (21), Internal jugular (19), and Ver- 
tebral (X., 2, 3, 4). 

There are numerous venous channels in the diploe be- 
tween the plates of the skull. 

The sinuses of the Dura Mater are venous channels sim- 
ilar to the veins, and communicating with the large venous 
trunks in the neck. 

The External Jugular Vein (X., 3; XII., 20) receives 
the greater part of the blood from the exterior of the cra- 
nium and deep parts of the face, being a continuation of 
the temporo-maxillary and posterior auricular veins. It 
commences in the substance of the parotid gland (XXXI., 
1), on a level with the angle of the lower jaw, and runs 
down the neck to about the middle of the clavicle (XL, 2), 
and terminates in the subclavian vein (XX., 74), on the 
outer side of the internal jugular (X., 2). This vein is 
occasionally double. It has two valves at its junction with 



ANATOMY AND PHYSIOLOGY. 1 53 

the subclavian and two others about an inch and a half 
above the clavicle. 

The Internal Jugular Vein (X., 2; XII., 10) collects the 
blood from the interior of the cranium, from the superfi- 
cial parts of the face, and from the neck. It commences 
at the jugular foramen, in the base of the skull, being 
formed by the coalescence of the lateral and inferior pe- 
trosal sinuses. It runs down the side of the neck in a 
vertical direction, lying at first on the outer side of the 
internal carotid artery and then on the outer side of the 
common carotid, and at the root of. the neck unites with 
the subclavian vein to form the vena innominata (XII., 17, 
18). It has a pair of valves at its junction with the 
subclavian. 

This vein receives in its course the facial, lingual, 
pharyngeal, superior and middle thyroid veins, and some- 
times the occipital. At its point of junction with the 
branch common to the temporal and facial veins, it be- 
comes greatly increased in size (XII., 25). 

The common carotid artery, the internal jugular vein, 
and the pneumogastric nerve in the neck are united in one 
sheath. 

The Anterior Jugular Vein (XII., 21) collects the blood 
from the integument and muscles in the middle of the 
anterior region of the neck. It passes down between the 
median line and the anterior border of the sterno-mastoid 
muscle, and at the lower part of the neck passes beneath 
that muscle to open into the termination of the external 
jugular or into the subclavian vein. Most frequently 
there are two of these veins, but occasionally only one. 



154 A COMPEND OF 

Just above the sternum the two anterior jugular veins 
communicate by a transverse trunk, which receives branches 
from the inferior thyroid veins. It also communicates 
with the internal and external jugular. There are no 
valves in this vein. 

The Cerebral Veins, very numerous, return the blood 
from the convolutions and substance of the cerebrum; 
they terminate in the sinuses by which the blood is passed 
to the jugulars. 

The Cerebellar Veins occupy the surface of the cerebel- 
lum; they terminate in the lateral sinuses. 

VEINS OF THE ARM AND HAND. 
(III., IV., XVII., XVIII.) 

The veins of the upper extremity are divided into two 
sets, superficial and deep. 

The Superficial Veins are placed immediately beneath 
the integument, between the two layers of superficial fascia; 
they commence in the hand chiefly on its dorsal aspect, 
where they form a more or less complete arch. 

The Deep Veins accompany the arteries and constitute 
the venae comites of those vessels. Both sets of vessels 
are provided with valves, which are more numerous in the 
deep than in the superficial. 

The superficial veins of the upper extremity (III.) are 
the Anterior Ulnar (1), Posterior Ulnar (k), Basilic (j), 
Eadial (n), Cephalic (i), Median (m), Median basilic, and 
Median cephalic. 



ANATOMY AND PHYSIOLOGY. 155 

The Anterior Ulnar Vein (1) commences on the anterior 
surface of the ulnar side of the hand and wrist, and as- 
cends along the inner side of the forearm to the bend of 
the elbow; here it joins with the posterior ulnar to form 
the basilic. It communicates with branches of the median 
vein in front and with the posterior ulnar behind. 

The Posterior Ulnar Vein (k) commences on the pos- 
terior surface of the ulnar side of the hand; and from the 
vein of the little finger. It runs on the posterior surface 
of the ulnar side of the forearm, and just below the elbow 
unites with the anterior ulnar vein to form the basilic. 

The Basilic (j) is formed by the coalescence of the an- 
terior and posterior ulnar veins. It is situated along the 
inner side of the elbow% receives the median basilic vein, 
and passing upw r ard along the inner side of the arm pierces 
the deep fascia, and ascends in the course of the brachial 
artery, terminating either in one of the venas comites of 
that vessel or in the axillary vein. 

The Radial Vein (n) commences from the dorsal surface 
of the thumb, index finger, and radial side of the hand, 
and ascends along the radial side of the forearm, and re- 
ceives numerous branches from both its surfaces. At the 
bend of the elbow it receives the median cephalic, when it 
becomes the cephalic vein. 

The Cephalic Vein (i) courses along the outer border of 
the biceps muscle to the upper third of the arm; it then 
passes in the interval between the jDectoralis major and 
Deltoid muscles, accompanied by the descending branch 
of the thoracico-acromialis artery and the upper external 
cutaneous bra-ncb of the musculo-spiral nerve, and termi- 



156 A COMPEND OF 

nates in the axillary vein, just below the clavicle. This 
vein is occasionally connected with the external jugular or 
subclavian, by a branch which passes upward in front of 
the clavicle. 

The Median Vein (m) collects the blood from the super- 
ficial structures on the palmar surface of the hand and 
middle line of the forearm, communicating witH the an- 
terior ulnar and radial veins. At the bend of the elbow it 
receives a branch of communication from the deep veins 
accompanying the brachial artery, and divides into two 
branches, the median cephalic and the median basilic, 
which diverge from each other as they ascend. 

The Median Cephalic passes outward and joins the ce- 
phalic vein. 

The Median Basilic passes inward and joins the basilic 
vein. 

The Deep Veins (XVII.) of the upper extremity follow 
the course of the arteries. They are generally two in 
number, one lying on each side of the corresponding artery, 
and they are connected at intervals by short transverse 
branches. These double venae comites commence in the 
fingers, as there are two digital veins, accompanying each 
artery along the sides of the fingers; these, uniting at their 
base, pass along the interosseous spaces in the palm, and 
terminate in the two superficial palmar veins. Branches 
from these vessels on the radial side of the hand accom- 
pany the superficialis volae, and on the ulnar side terminate 
in the deep ulnar veins (70). The deep ulnar veins, as they 
pass in front of the wrist, communicate with the interos- 
seous and superficial veins, and unite at the elbow with 



ANATOMY AM) PHYSIOLOGY. 157 

the deep radial veins, to form the venae comites of the 
brachial artery (69). 

The Interosseous Veins (72) are the veins accompanying 
the interosseous arteries. 

The Deep Palmar Veins accompany the deep palmar 
arch, being formed by branches which accompany the ram- 
ifications of that vessel. They communicate with the su- 
perficial palmar veins at the inner side of the. hand, and 
on the outer side terminate in the venae comites of the 
radial artery (71). At the wrist they receive a dorsal and 
a palmar branch from the thumb, and unite with the deep 
radial veins. Accompanying the radial artery, these ves- 
sels terminate in the venae comites of the brachial artery 
(69). 

The brachial veins are placed one on each side of the 
brachial artery, receiving branches corresponding with 
those given off from that vessel; at the lower margin of 
the axilla they unite with the basilic to form the axillary 
vein. 

The deep veins have numerous anastomoses, not only 
with each other, but also with the superficial veins. 

The Axillary Vein is of large size and formed by the 
continuation upward of the basilic vein. It commences 
at the lower part of the axillary space, increases in size as 
it ascends by receiving branches corresponding with those 
of the axillary artery, and terminates immediately beneath 
the clavicle at the outer margin of the first rib, where it 
becomes the subclavian vein (M). ft lies on the thoracic 
side of the axillary artery. Opposite the subscapularis it 
is joined by a large vein, formed by the junction of the 



158 A COMPEND OF 

venae comites of the brachial; and. near its termination it 
receives the cephalic vein. This vein is provided with a 
pair of valves opposite the lower border of the subscapu- 
lars muscle; valves are also found at the termination of 
the cephalic and subscapular veins. 

The Subclavian Vein (XVII., 66), the continuation 
of the axillary, extends from the outer margin of the first 
rib to the inner end of the sterno-clavicular articulation, 
where it unites with the internal jugular (XII., 19), to 
form the vena innominata (17, 18). It is in front of the 
subclavian artery, and rests in a depression on the first rib. 

It is provided with valves about an inch from its ter- 
mination in the vena innominata, just external to the en- 
trance of the external jugular vein. 

The Venze Innominate are two large trunks, placed 
one on each side of the root of the neck, and formed by 
the union of the internal jugular and subclavian veins of 
the corresponding side. 

The Eight Vena Innominata (17) is about an inch and 
a half in length. It receives the right vertebral vein and. 
right lymphatic duct, the right internal mammary, right 
inferior thyroid, and right superior intercostal veins. 

The Left Vena Innominata (18) is about three inches in 
length, and crosses obliquely from left to right across the 
upper and front part of the chest, to unite with its fellows 
of the opposite side, forming the superior vena cava (16). 

It lies in front of the three large arteries that arise from 
the arch of the aorta. This vessel is joined by the left 
vertebral, left inferior thyroid, left internal mammary, and 
the left superior intercostal veins, and occasionally some 



ANATOMY AND PHYSIOLOGY. 1 59 

thymic and pericardiac veins. There are no valves in the 
venae innominate. 

The Internal Mammary Veins, two in number to each 
artery, follow the course of that vessel. 

The Inferior Thyroid Veins arise in the venous plexus 
on the thyroid body (X., n), communicating with the mid- 
dle and superior thyroid veins. 

The Superior Intercostal Veins return the blood from 
the upper intercostal spaces. 

The Superior Vena Cava (XII., 16) receives the blood 
that is conveyed to the heart from the whole of the upper 
half of the body. It is two and a half or three inches in 
length, formed by the junction of the two venae innom- 
inate. It enters the pericardium about an inch and a half 
above the heart and terminates in the upper part of the 
right auricle. 

The Azygos Veins (XVI.) connect together the supe- 
rior and inferior venae cavae, supplying the place of those 
vessels in the part of the chest occupied by the heart. 

The Right Azygos (20) commences opposite the first or 
second lumbar vertebra, by a branch from the right lum- 
bar veins; sometimes by a branch from the renal vein, or 
from the inferior vena cava. It enters the thorax through 
the aortic opening in the Diaphragm, and passes along the 
right side of the vertebral column to the third dorsal ver- 
tebra, where it arches forward over the root of the right 
lung, and terminates in the superior vena cava, just before 
that vessel enters the pericardium. While passing through 
the aortic opening of the Diaphragm, it lies with the 
thoracic duct (17) on the right side of the aorta; and in 



l6o A COMPEND OF 

the thorax it lies upon the intercostal arteries, on the 
right side of the aorta and thoracic duct, covered by the 
pleura. It receives nine or ten intercostal veins of the 
right side (24), the vena azygos minor (21), several oeso- 
phageal, mediastinal, and vertebral veins; near its termina- 
tion the right bronchial vein; and is occasionally connected 
with the right superior intercostal vein. This vein and its 
branches are provided with valves. 

The intercostal veins on the left side, below the two or 
three upper intercostal spaces, usually form two trunks, 
named the left lower and the left upper azygos veins. 

The left lower or smaller azygos vein commences by a 
branch from one of the lumbar veins, or from the left 
renal vein. It passes into the thorax, through the left 
eras of the Diaphragm, and ascending on the left side of 
the spine, as high as the sixth or seventh dorsal vertebra, 
passes across the column, behind the aorta and thoracic 
duct, to terminate in the right azygos vein. It receives 
the four or five lower intercostal veins of the left side and 
some oesophageal and mediastinal veins. 

The Left Upper Azygos Vein receives veins from the in- 
tercostal spaces between the left superior intercostal vein 
and the highest branch of the left lower azygos. They are 
usually two or three in number, and join to form a trunk, 
w T hich ends in the right azygos vein or in the left lower 
azygos. Sometimes this vein is wanting, in which case 
the left superior intercostal vein will extend as low as the 
fifth or sixth intercostal space (23). 

The bronchial veins return the blood from the substance 
of the lungs; that of the right side opens into the vena 



ANATOMY AND PHYSIOLOGY. l6i 

asygos major, near its termination; that of the left side 
into the left superior intercostal vein. 

THE SPINAL VEINS. 

The numerous venous plexuses placed upon and within 
the spine may be arranged into four sets : 

1. Those placed on the exterior of the spinal column 
(the dorsi-spinal veins). 

2. Those in the interior of the spinal canal, between the 
vertebrae and the theca vertebralis (meningo-rachidean 
veins). 

3. The veins of the bodies of the vertebrae. 

4. The veins of the spinal cord (medulla-spinal). 

VEINS OF THE LOWER EXTREMITY. 

(V.) 

The veins of the lower extremity are superficial and 
deep, the superficial veins, like those of the arm, being 
placed beneath the integument, between the two layers of 
superficial fascia; the deep veins accompanying the arteries 
and forming the venae comites of those vessels. Both sets 
of veins are provided with valves, which are more numer- 
ous in the deep than in the superficial set. They are also 
more numerous in the lower limb than the upper. The 
superficial veins of the lower extremity are the internal or 
long saphenous vein and the external or short saphenous. 
There is the same want of uniformity in the anastomoses 



. 1 62 A COMPEND OF 

and branches of these veins as in those of the upper ex- 
tremity. 

The Internal Saphenous Vein (o) commences from a mi- 
nute plexus, which covers the dorsum and inner side of the 
foot; it ascends in front of the inner ankle and along the 
inner side of the leg, behind the inner margin of the tibia, 
accompanied by the internal saphenous nerve. At the 
knee it passes backward behind the inner condyle of the 
femur, ascends along the inside of the thigh, and passing 
through the saphenous opening in the fascia lata, termi- 
nates in the femoral vein about an inch and a half below 
Poupart's ligament. This vein receives in its course cuta- 
neous branches from the leg and thigh, and at the saphe- 
nous opening the superficial epigastric, superficial circum- 
flex iliac, and external pudic veins. The veins from the 
inner and back part of the thigh frequently unite to form 
a large vessel, which enters the main trunk near the saphe- 
nous opening; and sometimes those on the outer side of 
the thigh join to form a large branch, so that occasionally 
three large veins are seen converging from different parts 
of the thigh toward the saphenous opening. The internal 
saphenous vein communicates in the foot with the internal 
plantar vein; in the leg, with the posterior tibial veins, 
and also with the anterior tibial veins; at the knee, with 
the articular veins; in the thigh, with the femoral vein by 
one or more branches. The valves in this vein vary from 
two to six in number; they are more numerous in the 
thigh than in the leg. 

The External or Short Saphenous Vein is formed by 
branches which collect the blood from the dorsum and 



ANATOMY AND PHYSIOLOGY. 163 

outer side of the foot. It ascends behind the outer ankle, 
and along the outer border of the tendo Achillis, across 
which it passes at an acute angle to reach the middle line 
of the posterior aspect of the leg. Passing directly up- 
ward, it perforates the deep fascia in the lower part of 
the popliteal space, and terminates in the popliteal vein, 
between the heads of the Gastrocnemius muscle. It re- 
ceives numerous large branches from the back of the leg, 
and communicates with the deep veins on the dorsum of 
the foot, and behind the outer malleolus. This vein has 
only two valves, one of which is always found near its ter- 
mination in the popliteal vein. 

The Deep Veins of the lower extremity accompany the 
arteries and their branches, and are called the vence comites 
of those vessels. 

The external and internal plantar veins unite to form 
the posterior tibial (XIX., 8). They accompany the 
posterior tibial artery, and are joined by the peroneal 
veins (9). 

The anterior tibial veins are formed by a continuation 
upward of the venae comites of the dorsalis pedis artery. 

They perforate the interosseous membrane at the upper 
part of the leg, and form, by their junction with the pos- 
terior tibial, the popliteal vein. The valves in the deep 
veins are very numerous. 

The Popliteal Vein (XIX., 13) is formed by the junction 
of the venae comites of the anterior and posterior tibial 
vessels; it ascends through the popliteal space to the ten- 
dinous aperture in the Adductor magnus, where it becomes 
the femoral vein. In the lower part of its course it is 



164 A COMPEND OF 

placed internal to the artery; between the heads of the 
Gastrocnemius (XXXVIL, 1) it is close to its outer side. 

It receives the sural veins from the Gastrocnemius mus- 
cle, the articular veins, and the external saphenous. The 
valves of this vein are usually four in number. 

The Femoral Vein (XIX., 12) accompanies the femoral 
artery through the upper two-thirds of the thigh. In the 
lower part of its course it lies external to the artery ; higher 
up it is behind it; and beneath Poupart's ligament it lies 
to its inner side and on the same plane. It receives nu- 
merous muscular branches; the profunda femoris joins it 
about an inch and a half below Poupart's ligament, and 
near its termination the internal saphenous vein (XVI., 
61). The valves in this vein are four or five in number. 
The External Iliac Vein (XVI., 54) commences at the ter- 
mination of the femoral, beneath the crural arch, and pass- 
ing along the brim of the pelvis, terminates opposite the 
sacro-iliac symphysis by uniting with the internal iliac to 
form the common iliac vein. On the right side, it lies at 
first along the inner side of the external iliac artery; but 
as it passes upward, gradually inclines behind it. On the 
left side, it lies altogether on the inner side of the artery. 
It receives, immediately above Poupart's ligament, the epi- 
gastric and circumflex iliac veins. It has no valves. 

The Internal Iliac Vein (56) is formed by the vense comi- 
tes of the branches of the internal iliac artery, the umbili- 
cal arteries excepted. It receives the blood from the ex- 
terior of the pelvis and from the organs in the cavity of 
the pelvis. The internal iliac vein lies at first on the inner 
side and then behind the internal iliac artery, and termi- 



ANATOMY AND PHYSIOLOGY. 165 

nates opposite the sacro-iliac articulation, by uniting with 
the external iliac to form the common iliac vein. This 
vessel has no valves. 

The Common Iliac Veins are formed by the union of the 
internal and external iliac veins in front of the sacro-ver- 
tebral articulation; passing obliquely upward to the right 
side of the vertebrae, they terminate upon the interverte- 
bral substance between the fourth and fifth lumbar verte- 
brae, where the veins of the two sidfes unite at an acute 
angle to form the inferior vena cava. The right common 
iliac ascends behind and to the outside of its correspond- 
ing artery. The left common iliac is at first on the inner 
side of the corresponding artery, and then behind the 
right common iliac artery. No valves are found in these 
veins. 

The Inferior Vena Cava (XVI., 26) returns to the heart 
the blood from all the parts below the Diaphragm. It 
passes upward along the front of the spine, on the right 
side of the aorta, and having reached the under surface 
of the liver, is contained in a groove in its posterior border. 
It then perforates the tendinous centre of the Diaphragm, 
enters the pericardium, where it is covered by its serous 
layer, and terminates in the lower and back part of the 
right auricle (XII., 2). At its termination in the auricle 
it is provided with a valve, the Eustachian. This vein re- 
ceives in its course the following branches : Lumbar, Eight 
spermatic, Kenal, Suprarenal, Phrenic, and Hepatic, 



t 

166 A COMPEND OF 

POKTAL SYSTEM OF VEINS. 
(XVI.) 

The Portal Venous System is composed of-foui large 
veins, which collect the venous blood from the viscera of 
digestion. These veins are the Inferior mesenteric (41), 
Superior mesenteric (40), Splenic (33), and Gastric. These 
collect the blood from the stomach, spleen, pancreas, and 
intestines. The trunk formed by their union (vena portae) 
enters the liver and ramifies throughout its substance; and 
its branches, again emerging from that organ as the hepa- 
tic veins (29), terminate in the inferior vena cava (26). 
These veins are destitute of valves. 

The Portal Vein (30) is formed by the junction of the 
superior mesenteric, and splenic veins, in front of the vena 
cava, and behind the upper border of the great end of the 
pancreas. Passing upward through the right border of 
the lesser omentum to the under surface of the liver, it 
enters the transverse fissure, where it is somewhat enlarged, 
forming the sinus of the portal vein, and divides into two 
branches, which accompany the ramifications of the hepa- 
tic artery and hepatic duct throughout the substance of 
the liver. The portal vein is about four inches in length, 
and, while contained in the lesser omentum, lies behind 
and between the hepatic duct and artery, the former being 
to the right and the latter to the left. Within the liver 
the portal vein receives the blood from the branches of 
the hepatic artery. 

The ramifications of the hepatic artery are distributed 



ANATOMY AND PHYSIOLOGY. 1 67 

to the walls of the hepatic ducts and of the portal vein, to 
the capsule of Glisson, and to the peritoneal covering of 
the organ; while those of the portal vein pass into the 
glandular parenchyma, and, after traversing its substance 
as a capillary plexus, become continuous with the rootlets 
of the hepatic vein. Besides arterial blood, accordingly, 
which the liver receives in moderate quantity, it is supplied 
with venous blood in great abundance, received from the 
stomach, spleen, pancreas, and intestine. 

The complex organization of the liver, by reason of its 
peculiar relations to the digestive system, has made it ex- 
ceedingly difficult to arrive at definite conclusions concern- 
ing its functions. Whether its secretion, the bile, is wholly 
or partly excrementitious from the portal venous blood, 
or whether it has ingredients that are indispensable to the 
completion of the digestive processes, are questions yet 
unsettled among physiologists. 

The Renal Veins (XVI., 47, 50) are of large size, and 
placed in front of the renal arteries. The left is longer 
than the right, and passes in front of the aorta just below 
the origin of the superior mesenteric artery. It receives 
the left spermatic and the left inferior phrenic veins. It 
usually opens into the vena cava, a little higher than the 
right. 

THE KIDNEYS. 

(XVI., 37, 38.) 

The Kidneys are situated at the back part of the abdo- 
men, behind the peritoneum in the lumbar regions; each 
kidney extending from the eleventh rib nearly to the crest 



l68 A COMPEND OF 

of the ilium, but the right a little lower than the left, in 
consequence of the large space occupied by the liver. They 
are usually imbedded in a considerable quantity of fat, 
which principally holds them in position, though they are 
also to some extent sustained by the large blood-vessels 
with which they are connected. 

Each kidney is about four inches in length, two in 
breadth, and one inch in thickness, the left being some- 
what larger, though thinner, than the right. 

In the intricate internal structure of the kidney by which 
its secretion is extracted from the blood, and which is in- 
dispensable to the health of the body, are the Malpighian 
(XCIV., 2) bodies through which the function is per- 
formed. These are small rounded masses, exceedingly 
minute, of a deep red color, found only in the cortical 
structure of the kidney. Each of these little bodies are 
composed of two parts : a central glomerulus of vessels 
called a Malpighian tuft, and a membranous envelope, the 
Malpighian capsule; which latter is a small pouch-like 
commencement of a uriniferous tubule. 

The Suprarenal Capsules (XVI., 39) are two small flat- 
tened glandular bodies, of a yellowish color, situated at the 
back part of the abdomen, behind the peritoneum, and 
immediately in front of the upper part of either kidney; 
hence their name. These are ductless glands and their 
function is not known. 

THE CONSTITUENCY OF THE BLOOD. 

The Blood is a thick opaque fluid, varying in different 
parts of the body from a brilliant scarlet to a dark purple 



ANATOMY AND PHYSIOLOGY. 1 69 

or nearly black color. It has a slightly alkaline reaction 
and a specific gravity of 1055. It consists, first, of a nearly 
colorless, transparent, alkaline fluid, the plasma, contain- 
ing water, albuminous matters, and salts, in solution; and, 
secondly, of distinct corpuscles, or blood-globules, swim- 
ming in the liquid plasma. The globules form 40 per cent, 
the plasma about 60 per cent by volume of the entire 
mass. The specific gravity of the two is somewhat differ- 
ent. Their relative quantities, by weight, are more nearly 
equal than when estimated by volume, the exact propor- 
tions being as 45 to 55. 

The globules of the blood are of two kinds, red and 
white; of which the red are far more numerous, the pro- 
portion being about as 300 to 1. The red globules of the 
blood serve mainly as carriers of oxygen. The readiness 
with which they absorb this substance from the atmosjDhere, 
and their changes of color depending upon its supply or 
withdrawal, indicate that they have a special relation to 
its introduction and distribution in the body. They are 
composed of an albuminous and a coloring matter, with 
mineral salts and water. The most important ingredient 
of the red globules is their coloring matter, or haemoglobin. 

The physiological properties and functions of the white 
globules are not so distinct as those of the red. Their 
great inferiority in number shows that they are less im- 
portant for the immediate continuance of the vital opera- 
tions; and the same thing may be inferred from their want 
of strongly-marked specific characters. For while the red 
globules of the blood vary in appearance to a marked de- 
gree in different classes, orders, and families, the white 



I70 A COMPEND OF 

globules present the same general features of size, form, 
and structure everywhere. > 

The Plasma of the blood is a transparent, colorless, 
homogeneous liquid, in which the blood-globules are sus- 
pended. It consists of water holding in solution mineral 
salts and albuminous matters with various crystallizable 
substances of organic origin. Its albuminous matters are 
the most abundant and important of its solid ingredients. 
It contains some thirteen ingredients, of which, in 1,000 
parts, 902 are water, 53 are albumin, and 22 are paraglobu- 
lin. The albumin is doubtless the nutritions element par 
excellence. It in all probability supplies the greater part 
of the nitrogenous ingredients of the tissues, and provides 
for their daily nourishment and renovation. In this proc- 
ess it must suffer a variety of transformations, by which 
it is converted into the different albuminoid matters char- 
acteristic of muscular, nervous, glandular, and other struc- 
tures throughout the body. 

The ingredient next in abundance is par a globulin, the 
average quantity of which is about one-half of that of al- 
bumin. It is closely allied to albumin in its chemical 
relations, and no doubt also in its physiological action; 
and it is possible that either one of these substances may 
be an intermediate stage of production or metamorphosis 
of the other. 

The fibrinogen of the plasma, being 0.3 of the mass, is 
the substance that produces the solid fibrin of coagulated 
blood, 



ANATOMY AND PHYSIOLOGY, 171 



THE CAPILLARY CIRCULATION. 

The Capillary blood-vessels are minute inosculating tubes, 
distributed through all the periphery, permeating the vas- 
cular organs, and bringing the blood into close proximity 
with their tissues. They are continuous, on the one hand, 
with the terminal ramifications of the arteries, and, on the 
other, with the commencing rootlets of the veins. 

As the arterial ramifications approach the capillary sys- 
tem, they diminish in size, and leave their external coat of 
connective tissue. Their middle coat is, at the same time, 
reduced to a single layer of fusiform muscular fibres, which 
become gradually less numerous, and at last disappear al- 
together. The vascular canal is thus finally composed only 
of a single tunic continuous with the internal coat of the 
arterial ramification. These minute ramifications of the 
vascular system are necessarily microscopic in their pro- 
portions. 

It is during its passage through the capillaries that the 
blood serves for the nourishment of the tissues, and for 
absorption, secretion, or elimination. The nutritious in- 
gredients of the blood transude through their walls, and 
are appropriated by the tissues beyond. 

The conditions which influence the movement of the 
blood in the capillaries are somewhat different from those 
of the arterial and venous circulations. By the successive 
division of the arteries from the heart outward, the move- 
ment of pulsation is to a great extent equalized in their 
smaller branches. But in the neighborhood of the capil- 



172 A COMPEND OF 

lary system they suddenly break up into a terminal rami- 
fication of still smaller vessels, and so lose themselves at 
last in the capillary network. By this final increase of 
the vascular surface the equalization of the heart's action 
is completed. There is no longer any pulsating character 
in the force which acts on the circulating fluid ; and the 
blood moves through the capillary vessels under a contin- 
uous and uniform pressure. This pressure is sufficient to 
propel the blood through the capillary plexus into the veins. 

The complete circuit of the blood through the vascular 
system, from the time it leaves the heart until it returns, 
when no special obstacle is interposed, is estimated at about 
twenty seconds. 

The condition of the blood in its passage through the 
secreting glands, such as the salivary glands and the kid- 
neys, is peculiar. Throughout the muscular system the 
blood leaves the muscles of a dark color, and this is the more 
intense when they are in active contraction; but the dark 
color of the blood returning from these glands is inter- 
mittent. When the gland is in active secretion and its 
veins are discharging blood into the general circulation, it 
is largely arterial in its character, but when the gland is 
in repose, the blood in the veins proceeding from it is 
dark, similar to that returned from the muscles. This 
would seem to indicate that while the blood is supplying 
the secretion to the gland it suspends its supply of oxygen 
to its tissues, and as the circulation is continuous it passes 
on, leaving the gland measurably unchanged in color. 



ANATOMY AND PHYSIOLOGY. 1 73 

THE NERVOUS SYSTEM. 

This may be termed the great electro-magnetic system 
of the body, along whose lines pass signals of thought, 
sensation, and motion, under the control of the centre of 
government in the brain. It is the system through which 
all the functions of the body are performed, and without 
which there could be neither mental nor physical action. 
Bones, muscles, and viscera would all be inert without the 
powers it communicates through all the organism. 

The nervous system may be comprised under three gen- 
eral divisions : 1, a series of connected central organs called, 
collectively, the cerebrospinal centre or axis; 2, of the 
ganglia; and, 3, of the nerves. 

The Cerebrospinal Centre consists of two parts, the spinal 
cord and the encephalon; the latter consists of the cere- 
brum, the cerebellum, the pons Varolii, and the medulla 
oblongata. 

(XXXIX., XL., XLI.) 

The Brain {encepludon) is contained in the cranial cavity. 

The cerebrum occupies a considerable part of the cavity 
of the cranium, resting in the anterior and middle fossae 
of the base of the skull, and separated posteriorly from the 
cerebellum by the tentorium cerebelli. About the middle 
of its under surface is a narrow constricted portion, part 
of which, the crura cerebri, is continued onward into the 
pons Varolii below, and through it to the medulla oblon- 
gata and spinal cord; while another portion, the crura 
cerebelli, passes down into the cerebellum. 



174 A COMPEND OF 

CEREBRUM— UPPER SURFACE. 

The Cerebrum constitutes the largest portion of the eti- 
cephalon. It is divided into two lateral halves or hemi- 
spheres, right and left, by the great longitudinal fissure, 
which extends throughout the entire length of the cere- 
brum in the middle line, reaching down to the base of the 
brain in front and behind, but interrupted in the middle 
by a broad transverse commissure of white matter, the cor- 
pus callosum (XL., A; XLL, 4), which connects the two 
hemispheres together. This fissure lodges the falx cerebri, 
and indicates the original development of the brain by 
two lateral halves. 

Each hemisphere presents an outer surface, which is 
convex, to correspond with the vault of the cranium; an 
inner surface, flattened, and in contact with the opposite 
hemisphere (the two inner surfaces forming the sides of 
the longitudinal fissure); and an under surface or base, of 
more irregular form, which rests in front, on the anterior 
and middle fossae at the base of the skull, and behind 
upon the tentorium. 

Convolutions. The entire surface of each hemisphere 
presents a number of convoluted eminences, the convolu- 
tions, separated from each other by depressions (sulci) of 
various depths. The outer surface of each convolution, 
as well as the sides and bottom of the sulci, between them, 
are composed of gray matter, which is here called the cor- 
tical substance. The interior of each convolution is com- 
posed of white matter; and white fibres also blend with 
the gray matter at the sides and bottom of the sulci. By 



ANATOMY AND PHYSIOLOGY. 1 75 

this arrangement the convolutions are adapted to increase 
the amount of gray matter without occupying much addi- 
tional space, while they also afford a greater extent of sur- 
face for the termination of white fibres in gray matter. 

There is no accurate resemblance between the convolu- 
tions in different brains, nor are they symmetrical on the 
two sides of the same brain. 

The sulci are generally an inch in depth; they also vary 
in different brains, and in different parts of the same brain ; 
they are usually deepest on the outer convex surface of 
the hemispheres; the deepest is situated on the inner sur- 
face of the hemisphere, on a level with the corpus callosum, 
and corresponds to the projection in the posterior horn of 
the lateral ventricle, the hippocampus minor. 

The number and extent of the convolutions, as well as 
their depth, appear to bear a close relation to the intellec- 
tual power of the individual, as is shown in their increas- 
ing complexity of arrangement as we ascend from the low- 
est mammalia up to man. Thus they are absent in some 
of the lower order of mammalia, and they increase in num- 
ber and extent through the higher orders. In men they 
present the most complex arrangement. In the child at 
birth, before the intellectual faculties are exercised, the 
convolutions are simple, with few undulations; and the 
sulci between them are less deep than in the adult. In old 
age, when the mental faculties have diminished in activity, 
the convolutions become much less prominent. 

The convolutions on the outer convex surface of the 
hemisphere are especially characteristic of the human 
brain, but are seldom symmetrical on the two sides. 



i;6 A COMPEND OF 

Each hemisphere is divided into five lobes, the division 
being made by the main fissures and by imaginary lines 
drawn to connect them. The fissure of Sylvius (XXXIX., 
7; XL., B), between the anterior and middle lobes, and the 
fissure of Rolando (XXXIX., 8) are the principal fissures 
involved in these divisions. 

The chief convolutions which bound these several fis- 
sures are pretty constant, but the secondary convolutions, 
or those which form the bulk of the several lobes, vary 
greatly in their number and arrangement. 

The convolution of the corpus callosum (gyrus fornicatus) 
is always well marked. 

The supraorbital convolution on the under surface of the 
anterior lobe is well marked. 

The convolution of the longitudinal fissure bounds the 
margin of the fissure on the upper surface of the hemi- 
sphere. 

CEREBRUM— UNDER SURFACE. 
(XL.) 

The under surface of each hemisphere presents three 
lobes, anterior, middle, and posterior. 

The various objects on the under surface of the cere- 
brum, in the order as they exist from before backward, are : 
Longitudinal fissure. Corpus callosum (A) and its pedun- 
cles, Lamina cinerea, Olfactory nerve (1). Fissure of Syl- 
vius (B). Anterior perforated space. Optic commissure 
(2). Tuber cinereum. Infundibulum. Pituitary body. Cor- 
pora albicantia. Posterior perforated space. Crura cerebri. 



ANATOMY AND PHYSIOLOGY- 177 

The hemispheres are connected together by the corpus 
callosum, and the interval left between its under surface, 
the upper surface of the ganglia, and the parts closing the 
interpeduncular space, forms the general ventricular cav- 
ity. The upper part of this cavity is subdivided into two 
by a vertical septum, the septum lucidum, and thus the two 
lateral ventricles are formed. The lower part of the cav- 
ity forms the third ventricle, which communicates with 
the lateral ventricles above and with the fourth ventricle 
behind. The fifth ventricle is the interval left between 
the two layers composing the septum lucidum. 

The white matter of each hemisphere consists of three 
kinds of fibres: 1. Diverging or peduncular fibres, which 
connect the hemisphere with the cord and medulla ob- 
longata. 2. Transverse commissural fibres, which connect 
the two hemispheres. 3. Longitudinal commissural fibres, 
which connect distant parts of the same hemisphere. 

The cerebellum is situated in the inferior occipital fossae, 
beneath the under surface of the posterior lobes of the 
cerebrum. It is connected to the rest of the encephalon 
by connecting bands, called crura; of these, two ascend to 
the cerebrum, two descend to the medulla oblongata, and 
two blend together in front, forming the pons Varolii. 

The pons Varolii is that portion of the encephalon which 
rests upon the upper part of the basilar process and body 
of the sphenoid bone. It is the bond of union of the vari- 
ous segments above named, receiving, above, the crura 
from the cerebrum; at the sides, the crura from the cere- 
bellum; and below, the medulla oblongata. ■ 

The medulla oblongata (XLL, 9) is the upper enlarged 

12 



178 A COMMEND OF 

portion of the spinal cord within the cranium, and extends 
from the lower border of the pons Varolii to the upper 
border of the atlas, beneath the cerebellum, resting on the 
lower part of the basilar groove of the occipital bone. 

The average weight of the brain in the adult male is 49| 
oz., that of the female 44 oz. The prevailing weight of 
the brain in the male ranges between 46 oz. and 53 oz. ; 
and in the female, between 41 oz. and 47 oz. In the male, 
the maximum weight out of 278 cases was 65 oz., and the 
minimum weight 34 oz. The maximum weight of the adult 
female brain, out of 191 cases, was 56 oz., and the mini- 
mum weight 31 oz. It appears that the weight of the 
brain increases rapidly up to the seventh year, more slowly 
to between sixteen and twenty, and still more slowly to 
between thirty and forty, when it reaches its maximum. 
Beyond this period, as age advances and the mental facul- 
ties decline, the brain diminishes slowly in weight, about 
an ounce for each subsequent decennial period. 

The size of the brain appears to bear a general relation 
to the intellectual capacity of the individual. 

DUKA MATEE. 

The Dura mater is a fibrous membrane lining the interior 
of the skull and spinal column. It is the periosteum of 
ihe inner surface, and is continuous with the pericranium, 
which envelops the outer surface, through the various 
foramina in the base. It has numerous arteries, chiefly 
distributed to the bodies ascending from the carotid arte- 
ries and their branches. Its nerves are a branch of the 



ANATOMY AND PHYSIOLOGY. 1 79 

fourth and filaments from the Gasserian ganglion, from the 
ophthalmic nerve, and from the sympathetic. 

It dips down between the two hemispheres, and covers 
the upper surface of the cerebellum, passing in between 
it and the occipital lobe. 

ARACHNOID MEMBRANE. - 

The Arachnoid Membrane is extremely thin and is the 
serous membrane which envelopes the brain and spinal 
cord, and is then reflected on the inner surface of the dura 
mater. It is a shut sac consisting of a parietal and visceral 
layer. The parietal covers the inner surface of the dura 
mater, and passes with it between the hemispheres and 
between the occipital lobe and the cerebellum. 

PIA MATER. 

The Pia Mater is a vascular membrane deriving its blood 
from the internal carotid and vertebral arteries. It con- 
sists of a minute plexus of blood-vessels, and invests the 
entire surface of the brain, dipping down between the con- 
volutions, and is prolonged into the interior, forming the 
velum interpositum and choroid plexuses of the fourth 
ventricle. It sends branches deep down into the substance 
of the brain. 

THE SPINAL CORD. 

The Spinal cord (medulla spinalis) is the cylindrical 
elongated part of the cerebro-spinal axis which is contained 
in the vertebral canal. It extends from the upper border 
of the atlas to the lower border of the first lumbar verte- 



l8o A COMPEND OF 

bra, where it terminates in a slender filament of gray sub- 
stance, which is continued for some distance into the filum 
terminale. In form, the spinal cord is a flattened cylinder. 
It presents, on its anterior surface, along the middle line, 
a longitudinal fissure, the anterior median fissure; and, on 
its posterior surface, another fissure, which also extends 
along the entire length of the cord, the posterior median 
fissure. These fissures serve to divide the cord into two 
symmetrical halves, which are united in the middle line, 
throughout their entire length, by a transverse band of 
nervous substance, the commissure. 

If a transverse section of the spinal column be made, it 
will be seen to consist of white and gray nervous substance. 
The white matter is situated externally and forms the 
greater part. The gray substance occupies the centre, and 
is so arranged as to present on the surface of the section 
two crescentic masses placed one in each lateral half of the 
cord, united together by a transverse band of gray matter, 
the gray commissure. Each crescent has an anterior and 
posterior horn. The posterior horn is long and narrow, 
and approaches the surface of the postero-lateral fissure, 
near which it presents a slight enlargement. The anterior 
horn is short and thick, and does not quite reach the sur- 
face, but extends toward the point of attachment of the 
anterior roots of the nerves. 

THE GANGLIA. 

The Ganglia are nervous centres within the cranium 
and trunk, accessory to the cerebro-spinal axis, receiving 
and distributing nerves within the body. These will be 



ANATOMY AND PHYSIOLOGY. l8l 

considered as we proceed with the nerves with which they 
are connected. 

SPINAL NERVES. 
(XLII.) 

The Spinal Nerves are so called, because they proceed 
from the spinal cord and are transmitted through the in- 
tervertebral foramina, on either side of the spinal column. 
There are thirty-one pairs which are arranged into the 
following groups, corresponding to the region of the spine 
through which they pass: Cervical, 8 pairs; Dorsal, 12; 
Lumbar, 5 ; Sacral, 5 ; and Coccygeal, 1. Thus each group 
of nerves corresponds in number with the vertebrae in that 
region, except the cervical and coccygeal. 

Each spinal nerve arises by two roots, an anterior, or 
motor root, and a posterior, or sensory root (LIL) 

The anterior roots arise from a linear series of foramina 
on the antero-lateral column of the spinal cord. 

The posterior roots are all attached to the posterior white 
columns only, but some of them pass through the gray 
substance into both the lateral and anterior white columns. 
A ganglion is developed upon the posterior root of each of 
the cervical nerves, with the occasional exception of the 
first cervical. Immediately beyond the ganglion the two 
roots coalesce, their fibres intermingle, and the trunk thus 
formed passes out of the intervertebral foramen, and divides 
into an anterior branch for the supply of the anterior part 
of the body, and a posterior branch for the posterior part, 
each branch containing fibres from both roots. 



1 82 A COMPEND OF 

The anterior branches are connected by slender filaments 
from the sympathetic. In the dorsal region the anterior 
branches are completely separated from each other, and are 
uniform in their distribution ; but in the cervical, lumbar, 
and sacral regions, they form intricate plexuses previous 
to their distribution. 

The posterior branches pass backward, and, dividing into 
external and internal branches, are distributed to the mus- 
cles and integument behind the spine. The first cervical 
and the lower sacral nerves vary somewhat from this gen- 
eral description. 

Cervical Nerves. — The first four cervical nerves issue from 
the spinal column above the fifth vertebra, and their ante- 
rior branches form the cervical plexus (XLVIL, 20). The 
anterior branches of the four lower cervical nerves, together 
with the first dorsal nerve, form the brachial plexus 
(XLVIL, 21). 

The Cervical Plexus is situated opposite the four up- 
per vertebrae, resting upon the Levator anguli scapulse, 
and scalenus medius muscles, and covered in by the sterno- 
mastoid (L, 13, 14, 15). Its branches and their distribu- 
tion are as follows : 

Superficialis Colli arises from the second and third cer- 
vical nerves, divides beneath the platysma (I., 18) into two 
branches, which are distributed to the anterior and lateral 
parts of the neck. 

Auricularis Magnus arises from the second and third 
cervical nerves, ascends upon the sterno-mastoid muscle 
beneath the platysma to the parotid gland, where it di- 
vides into numerous branches. These are distributed to 



ANATOMY AM) PHYSIOLOGY. 183 

the muscles of the face, to the parotid gland (XXI., 1), and 

to the integument behind the ear. 

Occipitalis Minor arises from the second cervical nerve, 
and is distributed to the back part of the side of the head, 
supplying the integument and occipito-frontalis muscle 
(I., -i). A branch from this nerve supplies the Attolens 
aurem (L, 2), and the integument of the upper and back 
part of the auricle. 

The sternal, clavicular, and acromial branches arise from 
the third and fourth cervical nerves. 

The sternal branch crosses obliquely over the sterno-mas- 
toid, and supplies the integument as far as the median line. 

The clavicular branch crosses the clavicle and supplies 
the integument over the pectoral (II., 20) and deltoid mus- 
cles (II., 21), communicating with the cutaneous branches 
of the upper intercostal nerves. 

The acromial branch crosses obliquely across the outer 
surface of the Trapezius (I., 16, 17) and the acromion, and 
supplies the integument of the upper and back part of the 
shoulder. 

Communicating brandies pass from the loop between the 
first and second cervical nerves in front of the atlas to the 
pneumogastric, hypoglossal, sympathetic, and fifth cervical. 

Muscular branches proceed from the loop formed be- 
tween it and the second, to supply the Anterior recti and 
Eectus lateralis muscles. The Communicans noni is derived 
from the second and third cervical, descends and forms a 
loop with the descendens noni, and is distributed in the 
omohyoid muscle. 

The Phrenic Nerve arises from the third and fourth cer- 



1 84 A COMPEND OF 

vical nerves and receives a branch from the fifth. It passes 
down and enters the chest, and descends vertically to the 
Diaphragm (XVI., 27), where it divides into branches 
which are distributed to the under side of that organ. 

The two phrenic nerves differ somewhat in their relations 
in the thorax by reason of the difference of the two sides, 
occasioned by the inclination of the heart to the left side. 
The right nerve passes down on the outer side of the su- 
perior vena cava (XII., 16), and the left nerve passes down 
in front of the arch of the aorta (XII., 6). These nerves 
have connection w T ith the sympathetic (L., 1), the fifth 
and sixth cervical, the solar plexus, the hepatic plexus, 
the suprarenal capsule (XVI., 39), and inferior vena cava 
(XVI., 26). 

Communicating branches of the cervical plexus commu- 
nicate with the spinal accessory nerve, in the sterno-mastoid 
muscle, in the occipital triangle, and beneath the Trapezius. 

Muscular brandies are distributed to the Sterno-mastoid, 
Levator anguli scapulse, Scalenus medius, and Trapezius 
(I., 13, 14, 15, 16, 17). 

The posterior branches of the cervical nerves, with the 
exception of those of the first two, pass backward, and di- 
vide behind the posterior Intertransverse muscles into ex- 
ternal and internal branches. 

The external branches supply the muscles at the side of 
the neck. 

The internal branches of the third, fourth, and fifth 
nerves pass between the Semi-spinalis and Complexus mus- 
cles, and having reached the spinous processes, perforate 
the aponeurosis of the Splenius and Trapezius, and are 



ANATOMY AND PHYSIOLOGY. 185 

continued outward to the integuments over the Trapezius; 
those from the three lower cervical nerves are placed beneath 
the Semi-spinalis, which they supply. These internal 
branches supply the Complexus, Semi-spinalis colli, Inter- 
spinals, and Multifidus spinse. 

The posterior branch of the first cervical nerve escapes 
from the spinal canal between the occipital bone and the 
atlas, behind the vertebral artery, and supplies the Recti 
and Oblique muscles and the Complexus. 

The posterior branch of the second cervical nerve is the 
largest of all the posterior cervical nerves. It emerges 
from the spinal canal between the posterior arch of the 
atlas and lamina of the axis, below the Inferior oblique 
muscle, which it supplies, and receives a filament from the 
first cervical. It then divides into an external and internal 
branch, called the occipitalis major, is joined by a filament 
from the third cervical nerve, and ascending on the back part 
of the head, divides into two branches, which supply the in- 
tegument of the scalp communicating with the occipitalis 
minor. It gives off an auricular branch to the back part 
of the ear and muscular branches to the Complexus. 

The posterior branch of the third cervical differs from 
those of the other cervical nerves in its supplying an addi- 
tional filament to the integument of the occiput, and which 
supplies the skin on the lower back part of the head. 

The Brachial Plexus (XX., 75, 76) is formed by the 
anterior branches of the four lower cervical and first dor- 
sal nerves. It extends from the lower part of the side of 
the neck to the Axilla. It is very broad and presents little 
of a plexiform arrangement at its commencement, is nar- 



1 86 A COMPEND OF 

row opposite the clavicle, becomes broad, and forms a more 
dense interlacement in the axilla, and divides opposite the 
coracoid process into numerous branches for the supply of 
the upper limb. The fifth and sixth nerves unite near 
their exit from the spine into a common trunk; the seventh 
nerve joins this trunk near the outer border of the middle 
scalenus; and the three nerves thus form one large single 
cord. The eighth cervical and first dorsal nerves unite 
behind the Anterior scalenus into a common trunk. Thus 
two large trunks are formed, the upper one by the union 
of the fifth, sixth, and seventh cervical, and the lower 
one by the eighth cervical and the first dorsal. These 
two trunks accompany the subclavian artery to the axilla, 
lying upon its outer side, the trunk formed by the union 
of the last cervical and first dorsal being nearest to the 
vessel. Opposite to the clavicle, and sometimes in the 
axilla, each of these cords gives off a fasciculus, by the union 
of which a third trunk is formed, so that in the middle of 
the axilla three cords are found, one lying on the outer 
side of the axillary artery, one on its inner side, and one 
behind. The brachial plexus communicates with the 
cervical plexus by a branch from the fourth to the fifth 
nerve, and with the phrenic nerve by a branch from the 
fifth cervical, which joins that nerve on the Anterior 
scalenus muscle; the cervical and first dorsal nerves are 
also joined by filaments from the middle and inferior cer- 
vical ganglia of the sympathetic close to their exit from 
the intervertebral foramina. In the neck, the brachial 
plexus lies at first between the Anterior and Middle scaleni 
muscles, and then above and to the outer side of the sub- 



ANATOMY AND PHYSIOLOGY. 1 87 

clavian artery; it thou passes behind the clavicle and Sub- 
clavius muscle, lying upon the first serration of the Serra- 
tus magnus (II., 22), and the Subscapularis muscles. In 
the axilla it is placed on the outer side of the first 
portion of the axillary artery; it surrounds the artery 
in the second part of its course, one cord lying upon the 
outer side of that vessel, one on the inner side, and one 
behind it; and at the lower part of the axillary space gives 
off its terminal branches to the upper extremity. 

The branches of the brachial plexus above the clavicle 
are communicating branch, muscular branches, posterior 
thoracic, and Suprascapular. 

The communicating branch with the phrenic is derived 
from the fifth cervical nerve; it joins the phrenic on the 
Anterior scalenus muscle. 

The muscular branches supply the Longus colli, Scaleni, 
Khomboidii, and Subclavius muscles. 

The posterior thoracic supplies the Serratus magnus, and 
is remarkable for the length of its course. It arises by 
two roots from the fifth and sixth cervical nerves imme- 
diately after their exit from the spinal column. It extends 
along the side of the chest to the lower border of the 
Serratus magnus (II., 22) and supplies it with numerous 
filaments. 

The suprascapular arises from the cord formed by the 
fifth and seventh cervical nerves, passes outward beneath 
the Trapezius, enters the supraspinous fossa through the 
notch in the upper border of the scapula, and, passing be- 
neath the supraspinatus muscle, curves in front of the 
spine of the scapula to the infraspinous fossa. In the Su- 



188 A COMPEND OF 

praspinous fossa it gives off two branches to the Supraspi- 
natus muscle, and an articular filament to the shoulder- 
joint, and in the inf raspinous fossa it gives off two branches 
to the infraspinatus muscle, besides some filaments to the 
shoulder-joint and scapula. 

The brandies of the brachial plexus below the clavicle 
(XX) are Anterior thoracic, Subscapular, Circumflex, 
Musculocutaneous (78), Internal cutaneous, Lesser in- 
ternal cutaneous, Median, Ulnar (77), and Musculo-spiral 
(XLVIL, 22, 23, 24, 26). 

The Anterior Thoracic Nerves supply the Pectoral mus- 
cles (II., 20). 

The Subscapular Nerves supply the Subscapularis, Teres 
major, and Latissimus dorsi muscles. The Circumflex 
Nerve supplies some of the muscles and the integument 
of the shoulder, and the shoulder-joint. 

The Musculo- Cutaneous Nerve supplies some of the 
muscles of the arm and the integument of the forearm. 

The Internal Cutaneous Nerve arises from the inner 
cord in common with the ulnar and internal head of the 
median, and passing down the inner side of the arm, pierces 
the deep fascia with the basilic vein, about the middle of 
the limb, and, becoming cutaneous, divides into branches. 
One filament supplies the integument covering the Biceps 
(III., 28) muscle, nearly as far as the elbow. The anterior 
branch descends on the anterior surface of the ulnar side 
of the forearm, distributing filaments to the integuments 
as far as the wrist. The posterior branch passes obliquely 
downward on the inner side of the basilic vein, winds over 
the internal condyle of the humerus to the back of the 



ANATOMY AND PHYSIOLOGY. 1 89 

forearm, and descends on the posterior surface of its ulnar 
side to a little below the middle, distributing filaments to 
the integument. 

The Lesser Internal Cutaneous Nerve is distributed to 
the integuments on the inner side of the arm. 

The Median Nerve (XL VII., 22) passes from its origin 
in the brachial plexus down the middle of the arm and 
forearm to the hand, passing beneath the annular liga- 
ment. No branches are given off in the arm, but in the 
forearm its muscular branches supply all the superficial 
muscles except the Flexor carpi ulnaris; its anterior inter- 
osseous supplies the deep muscles on the front of the fore- 
arm, except the Flexor carpi ulnaris and part of the Flexor 
profundus digitorum. The palmar cutaneous branch 
arises near the wrist, and after passing the annular liga- 
ment supplies the skin over the ball of the thumb and 
the integument of the palm of the hand, anastomosing 
with the cutaneous branch of the ulnar. 

In the palm of the hand the median nerve divides into 
two branches, which in turn are subdivided and distributed 
to the thumb and fingers. These are called digital 
branches. 

The Ulnar Nerve (XLVIL, 23) is placed along the inner 
side of the arm and is distributed to the forearm and hand. 
It arises from the inner cord of the brachial plexus, and 
at the wrist crosses the annular ligament and divides into 
two branches. It distributes articular branches to the elbow- 
joint; Muscular branches, near the elbow, to the Flexor 
carpi ulnaris and Flexor profundus digitorum; cutaneous 
branches to the integument of the forearm; a dorsal cuta- 



I9O A COMPEND OF 

neous branch to the little and ring fingers; articular fila- 
ments to the wrist; a superficial palmar branch to the in- 
tegument of the inner side of the hand, and terminates in 
digital branches to the fingers and a deep palmar branch 
to the muscles of the palm and fingers. 

The Musculo- Spiral Nerve, the largest branch of the 
brachial plexus, supplies the muscles of the back part of 
the arm and forearms and the integument of the same parts, 
as well as that of the hand. It arises from the posterior 
cord of the brachial plexus. It winds round the humerus 
in the spiral groove with the superior profunda artery, 
passing from the inner to the outer side of the bone. Its 
muscular branches are internal, posterior, and external; 
they supply the triceps, Anconeus, Supinator longus, Ex- 
tensor carpi radialis longior, and Brachialis anticus. These 
branches are derived from the nerve at the posterior side 
of the arm. Its cutaneous branches are three in number, 
one internal and two external. The internal branch sup- 
plies the integument on the inner side of the arm as far as 
the olecranon. The two external cutaneous branches per- 
forate the outer head of the Triceps at its attachment to 
the humerus. The upper and smaller one follows the 
course of the cephalic vein to the front of the elbow, sup- 
plying the integument of the lower half of the upper arm 
on its anterior aspect. The lower branch pierces the deep 
fascia below the insertion of the Deltoid, and passes down 
the outer side of the arm and elbow, and along the back 
part of the radial side of the forearm to the wrist, supply- 
ing the integument in its course, and joining, near its ter- 
mination, with a branch of the external cutaneous nerve. 



ANATOMY AND PHYSIOLOGY. I9I 

The radial branch of the musculospiral nerve passes 
along the front of the radial side of the forearm to the 
commencement of its lower third, where it divides into 
two branches, external and internal. The external branch 
supplies the integument of the radial side and ball of the 
thumb, joining with the posterior branch of the external 
cutaneous nerve. The internal branch communicates, 
above the wrist, with a branch from the external cutaneous, 
and on the back of the hand forms an arch with the dor- 
sal branch of the ulnar nerve. It then divides into four 
digital nerves which are distributed to the thumb and fin- 
gers. The posterior interosseous branch of the Musculo- 
spiral winds to the back of the forearm, and descending 
to the back of the carpus, presents a gangliform enlarge- 
ment from which filaments are distributed to the ligaments 
and articulations of the carpus. It supplies all the muscles 
of the radial and posterior brachial regions, excepting the 
Anconeus, Supinator longus, and Extensor carpi radialis 
longior. This nerve being on the back of the arm is not 
shown on the manikin. 

DORSAL NERVES. 

The Dorsal Nerves are twelve in number on each side. 
The first appears between the first and second dorsal ver- 
tebrae and the last between the last dorsal and first lumbar. 

The roots increase in length from above downward, and 
remain, in connection with the spinal cord, within the canal 
for a distance equal to the height of two vertebrae, and at 
their exit each divides into two branches, a posterior (dor- 
sal) and an anterior (intercostal) branch. 



Ip2 A COMPEND OF 

The posterior branches of the dorsal nerves pass backward 
between the transverse processes, and divide into external 
branches. 

The external branches supply the Longissimus dorsi 
and Sacro-lumbalis and the Levatores costarum. 

The internal branches of the six upper nerves pass in- 
ward and supply the Multifidus spinae and Semi-spinalis 
dorsi muscles, and then become cutaneous beside the spi- 
nous processes. The internal branches of the six lower 
nerves are distributed to the Multifidus spinae without 
giving off any cutaneous filaments. 

The cutaneous branches of the dorsal nerves are twelve 
in number, the six upper being derived from the internal 
branches and the six lower from the external branches. 

INTERCOSTAL NERVES. 
(XLII.) 

The Intercostal Nerves (anterior branches of the dorsal 
nerves) are twelve in number on each side. They are dis- 
tributed to the parietes of the thorax and abdomen sepa- 
rately from each other. Each nerve is connected with the 
adjoining ganglion (a, a) of the sympathetic by one or two 
filaments. The six upper nerves, with the exception of 
the first, are distributed to the chest. The six lower sup- 
ply the chest and abdomen. 

The upper intercostal nerves pass forward in the inter- 
costal spaces with the intercostal blood-vessels. Near the 
Sternum they cross the internal mammary artery and sup- 



ANATOMY AND PHYSIOLOGY. 193 

ply the integument of the mamma and front of the chest, 
forming- the anterior cutaneous nerves of the thorax. 
There are numerous anterior and posterior lateral cutane- 
ous branches arising midway between the vertebrae and 
the sternum (XXXVIIL, 31, 32, 33). 

The lower intercostal nerves (excepting the last) are ar- 
ranged as the upper ones as far as the anterior extremities 
of the intercostal spaces, where they pass behind the costal 
cartilages. They supply the Eectus muscle and terminate 
in branches, which become subcutaneous, near the linea 
alba. These branches supply the integument in front. 
The lower intercostal nerves supply the intercostal and ab- 
dominal muscles, and about the middle of their course, 
give off lateral cutaneous branches which are distributed 
to the integument of the abdomen. 

LUMBAR NERVES. 

The Lumbar Nerves (XLIL, 29) are five in number on 
each side; the first appears between the first and second 
lumbar vertebrae, and the last between the last lumbar and 
the base of the sacrum (XLIL, c; XLIIL, k). 

The roots of the lumbar nerves are the largest and their 
filaments the most numerous of all the spinal nerves, and 
they are closely aggregated together at the lower end of 
the cord. The roots of these nerves have a vertical direc- 
tion, and are of considerable length, especially the lower 
ones, since the spinal cord descends only to the first lum- 
bar vertebra. As they issue from the spinal column they 
divide into anterior and posterior branches. 
13 



194 A COMPEND OF 

The posterior branches pass backward and divide into 
external and internal branches. 

The External branches supply the Erector spinas and 
intertransverse muscles. Cutaneous branches descend 
over the crest of the back part of the ilium, to be distrib- 
uted to the integument of the gluteal region, some of the 
filaments passing as far as the trochanter major. 

The Internal branches pass inward close to the articular 
processes of the vertebras, and supply the Multifidus spinas 
and Interspinalis muscles. The anterior branches of the 
lumbar nerves increase in size from above downward. At 
their origin they communicate with the lumbar ganglia of 
the sympathetic by long, slender filaments, which accom- 
pany the lumbar arteries round the sides of the bodies of 
the vertebras, beneath the Psoas muscle. The anterior 
branches of the four upper nerves are connected together 
in this situation by anastomotic loops, and form the lum- 
bar plexus. The anterior branch of the fifth lumbar, joined 
with a branch from the fourth, descends across the base of 
the sacrum to join the anterior branch of the first sacral 
nerve, and assist in the formation of the sacral plexus. 
The cord resulting from the union of these two nerves is 
called the lumbo-sacral nerve (XLIL, 30, 31). 

LUMBAE PLEXUS. 

The Lumbar Plexus (XLIL, 30) is formed by the loops 
of communication between the anterior branches of the 
four upper lumbar nerves. The plexus is narrow above, 
and occasionally connected with the last dorsal by a slen- 



ANATOMY AND PHYSIOLOGY. I95 

der branch, the dorsi-lumbar nerve; it is broad below, 
where it is joined to the sacral plexus by the lumbosacral 
cord. It is situated in the substance of the Psoas muscle 
near its posterior part, in front of the transverse processes 
of the lumbar vertebrae. 

The mode in which the plexus is formed is the follow- 
ing: The first lumbar nerve gives off the ilio-hypogastric 
and ilio-inguinal nerves and a communicating branch to 
the second lumbar nerve. The second gives off the exter- 
nal cutaneous and genito-crural and a communicating 
branch to the third nerve. The third nerve gives a de- 
scending filament to the fourth, and divides into two 
branches which assist in forming the anterior crural and 
obturator nerves; sometimes also it furnishes a part of the 
accessory obturator. The fourth nerve completes the for- 
mation of the anterior crural and the obturator and gives 
off a communicating branch to the fifth lumbar; some- 
times it also furnishes part of the accessory obturator. 
The branches of the lumbar plexus are the Ilio-hypogas- 
tric, Ilio-inguinal, Genito-crural, External cutaneous, Ob- 
turator, Accessory obturator, and Anterior crural nerves. 
The first two and part of the third supply the lower part 
of the parietes of the abdomen; all the remaining nerves 
supply the fore part of the thigh and the inner side of the 
leg(XLIL, e, 32, 33, 34, 35). 

The Iliohypogastric Nerve, issuing from the first lum- 
bar nerve, divides into two branches, the iliac and hypo- 
gastric. The iliac branch is distributed to the integument 
of the gluteal region. The hypogastric branch is distrib- 
uted to the integument covering the hypogastric region. 



I96 A COMPEND OF 

The Ilio-inguinal Nerve arises also from the first lum- 
bar nerve, and is distributed to the viscera in the lower 
portion of the pelvis. 

The Genito-crural Nerve arises from the second lumbar, 
and by a few fibres from the cord of communication be- 
tween it and the first. It divides into a genital and crural 
branch. 

The genital branch descends on the external iliac artery, 
sending a few filaments around that vessel; it then pierces 
the fascia transversalis, and passing through the abdomi- 
nal ring, descends to the viscera below. 

The f rural branch passes along- the inner margin of 
the Psoas muscle, beneath Pouparfs ligament, into the 
thigh, where it pierces the fascia lata, and is distributed 
to the integument of the upper anterior aspect of the 
thigh, communicating with the middle cutaneous nerve. 
A few filaments pass on to the femoral artery (XLIL, 
33). 

The External Cutaneous Nerve arises from the second 
lumbar, or from the loop between it and the third. It 
passes beneath Poupart's ligament into the thigh and di- 
vides into tw r o branches. 

The anterior branch subdivides into branches which are 
distributed to the integument along the outer anterior part 
of the thigh as far down as the knee. This nerve occasion- 
ally communicates with the long saphenous nerve. The pos- 
terior branch subdivides into branches distributed to the 
outer posterior surface of the thigh, supplying the integu- 
ment as far as the middle of the thigh. 

The Obturator Nerve (XLIL, 35) arises by two branches: 



ANATOMY AND niYSIOLOGY. 1 97 

one from the third and the other from the fourth lumbar 
nerve. It descends to the upper part of the obturator fo- 
ramen (XLIIL, m), where it enters the thigh and divides 
into anterior and posterior branches, separated by the Ad- 
ductor brevis muscle. These branches are distributed to the 
Obturator externus and Adductor muscles of the thigh (V., 
40, 48), the articulations of the hip and knee, and occasion- 
ally the integument of the thigh and leg. Some filaments 
are distributed to the femoral and popliteal arteries 
(XIX., 1,3). 

The Accessory Obturator Nerve is oi small size and some- 
times does not exist at all; its function, as its name indi- 
cates, being to aid in the work of the obturator. When it 
is absent, additional branches from the obturator perform 
its functions. 

The Anterior Crural Nerve (XLIL, 33) is the largest 
branch of the lumbar plexus. It supplies muscular branches 
to the Iliacus, Pectineus, and all the muscles on the front 
of the thigh, excepting the Tensor vaginae femoris; cuta- 
neous filaments to the front and inner side of the thigh and 
to the leg and foot; and articular branches to the knee. 
It arises from the third and fourth lumbar nerves, receiv- 
ing a fasciculus from the second. It descends through the 
fibres of the Psoas muscle and issues from the pelvis be- 
neath Poupart's ligament (II., 26), into the thigh, and di- 
vides into an anterior o,r cutaneous and posterior or mus- 
cular part. 

Within the pelvis the anterior crural gives off from its 
outer side some small branches to the Iliacus and a branch 
to the femoral artery, which is distributed upon the upper 



I98 A COMPEND OF 

part of that vessel. Sometimes this branch arises lower 
down in the thigh. 

External to the pelvis the following branches are given 
off: From the anterior division, Middle cutaneous, Internal 
cutaneous, and Long saphenous; from the posterior divi- 
sion, Muscular and Articular. The anterior division by 
its divisions and subdivisions is distributed to the front of 
the leg and foot. The two branches of the posterior divi- 
sion supply the Pectineus and all the muscles in the front 
of the thigh except the Tensor vaginae femoris and Sarto- 
rius and the capsular ligament and synovial membrane of 
the knee-joint. 

SACEAL AND COCCYGEAL NEEVES. 

The sacral nerves are five in number on each side. The 
four upper ones pass from the sacral canal through the 
sacral foramina; the fifth through the foramen between 
the sacrum and coccyx. 

The roots of origin of the upper sacral (and lumbar) 
nerves are the largest of all the spinal nerves; while those 
of the lowest sacral and coccygeal nerves are the smallest. 

These roots are longer than other spinal nerves by rea- 
son of the termination of the spinal cord within the first 
lumbar vertebras. The roots of origin of these nerves are 
called collectively cauda equina. .Each of these nerves, 
as with other spinal nerves, divides into anterior and pos- 
terior branches. The posterior branches of the three upper 
ones are divided into internal and external. The external 
branches communicate with one another, and with the last 



ANATOMY AND PHYSIOLOGY. I99 

lumbar and fourth sacral nerves, by means of anastomizing 
loops. These branches pass outward to the outer surface 
of the gro.it sacro-sciatic ligament, where they form a sec- 
ond series of loops beneath the Gluteus maximus muscle. 
Cutaneous branches from this second series of loops pierce 
the muscle and supply the integument over the posterior 
part of the gluteal region (XXXVI., 1). The two lower 
posterior sacral nerves join with each other and with the 
coccygeal nerve so as to form loops on the back of the sa- 
crum, filaments from which supply the integument over 
the coccyx. 

The first, second, and third sacral nerves, with the 
lumbo-sacral, unite to form the sacral plexus (XLIL, 31.) 

All the anterior sacral nerves connect with the sacral 
ganglia of the sympathetic (a). 

The fourth anterior sacral nerve sends a branch to the 
sacral plexus. The remaining portion of the nerve divides 
into visceral and muscular branches; and a communicating 
filament descends to join the fifth sacral nerve. The 
visceral branches are distributed to the viscera of the pelvis 
communicating with the sympathetic nerve, thus entering 
into the structure of the hypogastric plexus (LI., 10). The 
'muscular branches are distributed to the Levator ani, 
Coccygeus, and Sphincter ani. Cutaneous filaments are 
also distributed to this portion of the pelvis. 

The fifth anterior sacral nerve passes from the lower 
end of the sacral canal, pierces the Coccygeus muscle, and 
descends upon its anterior surface to the tip of the coccyx, 
where it perforates that muscle, to be distributed to the 
integument over the back part and sides of the coccyx. 



200 A COMPEND OF 

This nerve communicates above with the fourth sacral and 
below with the coccygeal nerve and supplies the Coccygeus 
muscle. » 

The anterior branch of the coccygeal nerve is a delicate 
filament which escapes at the termination of the sacral 
canal. It pierces the sacro-sciatic ligament and Coccygeus 
muscle, is joined by a branch from the fifth anterior sacral/ 
and becomes lost in the integument at the back part and 
sides of the coccyx. 

SACKAL PLEXUS. 

The Sacral Plexus (XLIL, 31) is formed by the lumbo- 
sacral, the anterior branches of the three upper sacral 
nerves, and part of the fourth. These nerves proceed in 
different directions; the upper ones obliquely downward 
and outward, the lower one nearly horizontally, and they 
all unite into a single broad flat cord. The sacral plexus 
is triangular in form, its base corresponding with the exit 
of the nerves from the sacrum, its apex, with the lower 
part of the great sacro-sciatic foramen (XLIIL, 1). It 
rests upon the anterior surface of the Pyriformis, and is 
covered in front by the pelvic fascia, which separates it 
from the sciatic and pudic branches of the internal iliac 
artery and from the viscera of the pelvis. 

The branches of the sacral plexus are Muscular, Supe- 
rior gluteal, Pudic, Small sciatic, and Great sciatic (XLIL, 
34). 

The muscular branches supply the Pyriformis, Obturator 
intern us, the two Gemelli, and the Quadratus femoris. 



ANATOMY AND PHYSIOLOGY. 201 

The Superior Gluteal Nerve arises from the back part of 
the lumbo-sacral, and passing out of the pelvis through the 
sacro-sciatic foramen accompanied by the gluteal vessels, 
divides into superior and inferior branches. 

The superior branch supplies the Gluteus minimus and 
Gluteus medius muscles (XXXVI. , 1). 

The inferior branch crosses obliquely between the two 
above-mentioned muscles, distributing filaments to both, 
and terminates in the Tensor vaginae femoris, extending 
nearly to its lower end. 

The Pudic Nerve arises from the lower part of the 
sacral plexus, and leaves the pelvis through the sacro- 
sciatic foramen. It then crosses the spine of the ischium 
and re-enters the pelvis through the lesser sacro-sciatic 
foramen. It accompanies the pudic vessels upward and 
forward along the outer Avail of the ischio-rectal fossa, be- 
ing covered by the obturator fascia, and divides into two 
terminal branches; other numerous branches of the pudic 
nerve are distributed to the viscera of the pelvis and thighs. 

The Small Sciatic nerve supplies the integument of the 
perineum and back part of the thigh and leg, and one 
muscle, the Gluteus maximus. It is usually formed by the 
union of tw T o branches which arise from the lower part of 
the sacsal plexus. It descends beneath the Gluteus maxi- 
mus (XXXVI., 1) with the sciatic artery, and at the lower 
border of that muscle passes along the back part of the 
thigh, beneath the fascia lata, to the lower part of the 
popliteal region, below the knee-joint where it pierces 
the fascia and becomes cutaneous. It then accompanies 
the external saphenous vein below the middle of the leg, 



202 A COMPEND OF 

its terminal filaments communicating with the external 
saphenous nerve. 

The Great Sciatic Nerve (LVIIL, 1) supplies nearly the 
whole of the integument of the leg, the muscles of the 
back of the thigh, and those of the leg and foot. It is the 
largest nervous cord in the body, measuring three-quarters 
of an inch in breadth, and is the continuation of the lower 
part of the sacral plexus (XLIL, 31). It passes out of the 
pelvis through the great sacro-sciatic foramen (XLIIL, 1) 
below the Pyriformis muscle. It descends between the 
trochanter major and tuberosity of the ischium along the 
back part of the thigh, to about its lower third, where it 
divides into two large branches, the internal and external 
popliteal nerves (XLIX., 36). 

The brandies of the nerve before its division are articu- 
lar and muscular. 

The articular branches supply the hip-joint, perforating 
its fibrous capsule posteriorly. 

The muscular brandies are distributed to the Biceps, 
Semi-tendinosus, and the Semi-membranosus, and a branch 
to the Adductor magnus. 

The Internal Popliteal § Nerve (LVIIL, 2), the larger of 
the two terminal branches of the great sciatic, descends 
along the back part of the thigh, through the middle of 
the popliteal space, to the lower part of the popliteus mus- 
cle, where it passes with the artery beneath the arch of the 
Soleus, and becomes the posterior tibial. It lies at first 
very superficial, and at the outer side of the popliteal ves- 
sels; opposite the knee-joint it is in close relation with 
the vessels, and crosses the artery to its inner side. 



ANATOMY AND PHYSIOLOGY. 203 

The brandies of this nerve are articular, muscular, and 
a cutaneous branch, the short saphenous nerve. 

The articular branches supply the knee-joint. 

The muscular bra aches, four or five in number, arise 
from the nerve as it lies between the two heads of the 
Gastrocnemius muscle. They supply that muscle, the 
Plantaris, Soleus, and Popliteus. 

The short saphenous nerve descends between the two 
heads of the Gastrocnemius muscle, and about the middle 
of the back of the leg pierces the deep fascia, and receiv- 
ing a communicating branch from the external popliteal 
nerve. The nerve then continues its course down the leg 
near the outer margin of the tendo Achillis, in company 
with the external saphenous vein, winds round the outer 
malleolus, and is distributed to the integument along the 
outer side of the foot and little toe, communicating on the 
dorsum of the foot with the musculo-cutaneous nerve. 

The Posterior Tibial nerve, the extension of the internal 
popliteal, passes along the back part of the leg with the 
posterior tibial vessels to the interval between the inner 
malleolus and the heel, where it divides into the external 
and internal plantar nerves. In the lower part of the leg 
it is placed parallel with the inner margin of the tendo 
Achillis. 

The branches of the posterior tibial nerve are muscular 
and plantar-cutaneous. 

The muscular branches supply the Tibialis posticus, 
Flexor longus digitorum, and Flexor longus pollicis mus- 
cles; the branch to the latter muscle accompanying the 
peroneal artery. 



204 A COMPEND OF 

The plantar-cutaneous branch perforates the internal 
annular ligament and supplies the integument of the heel 
and inner side of the sole of the foot. 

The internal plantar nerve, the larger of the two terminal 
branches of the posterior tibial, accompanies the internal 
plantar artery along the inner side of the foot. It passes 
forward between the Abductor pollicis and Flexor brevis 
digitorum, divides opposite the bases of the metatarsal 
bones into four digital branches, and communicates with 
the external plantar nerve. 

The external plantar nerve completes the nervous supply 
to the structures of the foot. 

The External Popliteal or Peroneal Nerve (XLIX., 3§), 
about half the size of the internal popliteal, descends ob- 
liquely along the outer side of the popliteal space to the 
fibula (XLV., v) close to the margin of the Biceps muscle. 
About an # inch below the head of the fibula it pierces the 
origin of the Peroneus longus, and divides beneath that 
muscle into the anteiior tibial and musculo-cutaneous 
nerves. 

The branches of the peroneal nerve, previous to its divi- 
sion, are articular and cutaneous. The articular branches 
are distributed to the knee-joint. The cutaneous branches 
supply the integument along the back part and outer side 
of the leg, as far as its middle or lower part; a branch 
sometimes continues down to the heel. 

The Anterior Tibial Nerve (XLIX., 38) commences at 
the bifurcation of the peroneal nerve, between the fibula 
and the upper part of the Peroneous longus, passes obliquely 
forward beneath the Extensor longus digitorum to the 



ANATOMY AND PHYSIOLOGY. 205 

fore part of the interosseous membrane, and reaches the 
outer side of the anterior tibial artery above the middle 
of the leg; it then descends with the artery to the front 
of the ankle-joint, where it divides into an external and 
internal branch. This nerve lies first on the outer side of 
the anterior tibial artery, then in front of it, and again at 
its outer side at the ankle-joint. 

The branches of the anterior tibial are the muscular 
nerves to the Tibialis anticus, Extensor longus digitorum, 
Peroneus tertius, and Extensor proprius pollicis muscles. 

The external or tarsal branch of the anterior tibial passes 
outward across the tarsus, and having become ganglionic, 
supplies the Extensor brevis digitorum and the articula- 
tions of the tarsus and, metatarsus. 

The internal branch, the continuation of the nerve, 
accompanies the dorsalis pedis artery along the inner side 
of the dorsum of the foot, and at the first interosseous space 
divides into two branches, which supply the adjacent sides 
of the great and second toes, communicating with the in- 
ternal division of the musculo-cutaneous nerve. 

The Musculo-cutaneous Xerve (XLIX., 39) supplies the 
muscles on the fibular side of the leg and the integument 
of the dorsum of the foot. It passes forward between the 
peronei muscles and the Extensor longus digitorum, 
pierces the deep fascia at the lower third of the leg on its 
front and outer side, and divides into two branches. This 
nerve, in its course between the muscles, gives off muscu- 
lar branches to the Peroneus longus and brevis, and cuta- 
neous filaments to the integument of the lower part of the 
leg. The internal branch passes in front of the ankle- 



2o6 A COMPEND OF 

joint and along the dorsum of the foot, supplying the 
inner side of the great toe and the adjoining sides of the 
second and third toes. It also supplies the integument of 
the inner ankle and inner side of the foot, communicating 
with the internal saphenous nerve, and joins with the 
anterior tibial nerve between the great and second toes. 
The external branch, the larger, passes along the'buter side 
of the dorsum of the foot, to be distributed to the adjoin- 
ing sides of the third, fourth, and fifth toes. It also sup- 
plies the integument of the outer ankle and outer side of 
the foot, communicating with the short saphenous nerve 
(XLIX.). 

THE SYMPATHETIC KEKVE. 

(LI.) 

The Sympathetic nerve is so called from the opinion 
entertained that through it is produced a sympathy between 
the affections of distant organs. It consists of a series of 
ganglia, connected together by intervening cords (a) ex- 
tending on each side of the vertebral column from the base 
of the skull to the coccyx (XLIL, a). It may, moreover, 
be traced up into the head, where the ganglia, which are 
all in connection with the fifth cranial nerve (XLL, 14), 
occupy spaces between the cranial and facial bones. These 
two gangliated cords lie parallel with one another as far 
as the sacrum, on which bone they converge, communicat- 
ing together through a single ganglion (ganglion impar) 
placed in front of the coccyx (L., 9). Some anatomists 
also state that the two cords are joined at their cephalic 



ANATOMY AND PHYSIOLOGY. lO*] 

extremity through a small ganglion (the ganglion of Ribes) 
situated upon the anterior communicating artery. More- 
over, the chains of opposite sides communicate between 
these two extremities in several parts by means of the 
nervous cords that arise from them. The sympathetic 
ganglia are located thus: Cephalic, 4; Cervical, 3; Dorsal, 
12; Lumbar, 4; Sacral, 5; Coccygeal, 1. 

Each ganglion may be regarded as a distinct centre, from 
or to which branches pass in various directions. These 
branches may be thus arranged: 

1. Branches of communication between the ganglia. 2. 
Branches of communication with the cerebral or spinal 
nerves. 3. Primary branches passing to be distributed to 
the arteries in the vicinity of the ganglia and to the vis- 
cera, or proceeding to other ganglia placed in the thorax, 
abdomen, or pelvis. 

The location and arrangement of these ganglia would 
seem to indicate that they are secondary nerve centres for 
the purpose of combining and distributing special nervous 
influences to the vital organs within the trunk. They com- 
bine both spinal and sympathetic fibres in their structure, 
and in the various ganglia and plexuses into which they 
send filaments there are combinations with the filaments 
from the pneumogastric descending from the medulla 
oblongata, and distributed to the heart, lungs, and stomach. 

Furthermore, all the sympathetic ganglia receive fila- 
ments from the cerebro-spinal nerves, the fibres of which, 
there is reason to believe, pass through the ganglion to the 
peripheral branches of the sympathetic system. This is 
inferred from the fact that many of these fibres cannot be 



2o8 A COMPEND OF 

seen either to originate or terminate in the ganglion, and 
also from the paralyzing effect produced on a muscular 
organ supplied with sympathetic fibres by division of the 
cerebro-spinal nerve which communicates with its gan- 
glion. This is especially shown by dilatation of the pupil 
following division of the oculo-motorius nerve, which sup- 
plies the iris with a motor branch through the ophthalmic 
ganglion. The numerous filaments supplied by the pneu- 
mogastric nerve (LI., 2) to the cardiac branches of the 
sympathetic and to the cardiac plexus (4) afford a strik- 
ing instance of the same kind. 

All the internal organs of the body doubtless receive 
filaments from both the sympathetic and spinal systems 
of nerves. The cerebro-spinal nerves are in greatest abun- 
dance and manifest their most striking properties in the 
organs of animal life; those of the sympathetic system pre- 
ponderate in the organs of nutrition and in their influence 
on the functions of circulation, secretion, and growth. 

The nerves of the sympathetic system are distributed to 
glands and mucous membranes mostly destitute of general 
sensibility, and to muscular fibres which are independent 
of the will. Each ganglion is connected by its nerves of 
distribution with special organs. 

The first sympathetic ganglion in the head is the ophthal- 
mic in the orbit of the eye, on the outer aspect of the optic 
nerve. It communicates by slender filaments with the 
carotid plexus of sympathetic nerves, receives a motor root 
from the oculo-motorius and a sensitive root from the 
ophthalmic division of the fifth pair. Its filaments of dis- 
tribution, known as the " ciliary nerves," pass forward 



ANATOMY AND PHYSIOLOGY. 20g 

upon the eyeball, pierce the sclerotic, and terminate in 
the iris (LXXIL). 

The next is the spheno-palatine ganglion, in the spheno- 
maxillary fossa. It communicates, like the preceding, 
with the carotid plexus; receives a motor root from the 
facial nerve, and a sensitive root from the superior maxil- 
lary division of the fifth pair. Its filaments are distributed 
to the levator palati and uvular muscles, to the mucous 
membrane of the posterior part of the nasal passages, and 
to that of the hard and soft palate. 

The third is the submaxillary ganglion, connected with 
the submaxillary gland (XXXI., 3). It communicates with 
the superior cervical ganglion of the sympathetic by fila- 
ments accompanying the external carotid and facial arte- 
ries. It derives its sensitive filaments from the lingual 
branch of the fifth pair, and its motor filaments from the 
facial nerve, by the chorda tympani. Its branches of dis- 
tribution pass mainly to the submaxillary gland and duct. 

The last sympathetic ganglion in the head is the otic 
ganglion, situated beneath the base of the skull on the 
inner side of the inferior maxillary division of the fifth 
pair. It receives filaments of communication from the 
carotid plexus; a motor root from the facial by the small 
superficial petrosal nerve, as well as one or two short fibres 
from the inferior maxillary division of the fifth pair; and 
a sensitive root from the glossopharyngeal by the nerve of 
Jacobson. Its branches are sent to the internal muscle of 
the malleus in the middle ear (tensor tympani) and to the 
mucous membrane of the tympanum and Eustachian tube. 

The continuation of the sympathetic nerve in the neck 
14 



210 A COMPEND OF 

consists of two and sometimes three ganglia, the superior, 
middle, and inferior, communicating with each other and 
the cervical spinal nerves. Its filaments follow the course 
of the carotid artery and its branches, forming, by their 
inosculations, the corresponding arterial plexuses, and sup- 
plying fibres of distribution to the thyroid gland, the 
larynx, trachea, pharynx, and oesophagus. By the superior, 
middle, and inferior cardiac nerves it also supplies fibres 
to the cardiac plexus and through it to the heart. (See 
XV. and Key.) 

The Superior Cervical Ganglion is placed opposite the 
second and third cervical vertebrae and sometimes as low 
as the fourth or fifth. 

The Middle Cervical Ganglion (thyroid) is the smallest 
of the three cervical ganglia, and is occasionally altogether 
wanting. It is placed opposite the fifth cervical vertebra, 
usually upon or close to the inferior thyroid artery; hence 
its name, " thyroid ganglion." 

The Inferior Cervical Ganglion is situated between the 
base of the transverse process of the last cervical vertebra 
and the neck of the first rib, on the inner side of the supe- 
rior intercostal artery. 

CARDIAC NERVES. 

The Cardiac Nerves are three in number on each side : 
superior, middle, and inferior, one being derived from each 
of the cervical ganglia. 

The superior cardiac nerve arises by two or more branches 
from the superior cervical ganglion. It runs down the 



ANATOMY AND PHYSIOLOGY. 211 

neck behind the common carotid artery (X., 1) and crosses 
in front of the inferior thyroid artery and the recurrent 
laryngeal nerve. 

The middle cardiac nerve, the largest of the three, arises 
from the middle cervical ganglion, or from the cord be- 
tween the middle and inferior ganglia. On the right side 
it descends behind the common carotid artery and in 
front of or behind the subclavian artery; it then descends 
on the trachea and joins the deep cardiac plexus (LI., 4). 
On the left side it enters the chest between the left 
carotid and subclavian arteries, and joins the left side of 
the deep cardiac plexus. 

The inferior cardiac nerve arises from the inferior cer- 
vical or first thoracic ganglion. It passes down behind the 
subclavian artery and along the front of the trachea, to 
join the deep cardiac plexus. 

The great or deep cardiac plexus (4) is situated in front 
of the trachea at its bifurcation, above the point of divi- 
sion of the pulmonary artery and behind the arch of the 
aorta. It is formed by the cardiac nerves derived from the 
cervical ganglia of the sympathetic and the cardiac 
branches of the recurrent laryngeal and pneumogastric 
(2). The branches derived from the great cardiac plexus 
form the posterior coronary plexus and part of the ante- 
rior coronary plexus; while a few filaments proceed to the 
pulmonary plexuses and to the auricles of the heart. 

In the chest, the communications of the sympathetic 
ganglia* with the spinal nerves are double; each ganglion 
receiving two filaments from the intercostal nerve next 
above it. The nerves originating from the ganglia are 



212 A COMPEND OF 

distributed to the plexuses on the thoracic aorta, and to 
those of the lungs and oesophagus. 

The sympathetic ganglia in the thorax usually corre- 
spond in number to the vertebrae, but sometimes two of 
them coalesce so that their number is uncertain. They 
are placed on each side of the spine, resting against the 
heads of the ribs. They are connected together by cord- 
like prolongations from their substance. The internal 
branches of the six lower ganglia distribute filaments to 
the aorta, and unite to form the three splanchnic nerves. 
These are named the great, the lesser, and the smallest or 
renal splanchnic. 

The great splanchnic nerve is formed by branches from 
the thoracic ganglia between the sixth and tenth, receiving 
also filaments from all the ganglia above the sixth (a). 
These roots unite to form a large round cord of consider- 
able size. It descends obliquely inward in front of the 
bodies of the vertebrae along the posterior mediastinum, 
perforates the crus of the diaphragm, and terminates in 
the semi-lunar ganglion (7), distributing filaments to the 
renal plexus and suprarenal capsule. 

The lesser splanchnic nerve is formed by filaments from 
the tenth and eleventh ganglia and from the cord between 
them. It pierces the diaphragm with the preceding 
nerve and joins the ccelic plexus. It communicates in 
the chest with the great splanchnic nerve and sends fila- 
ments to the renal plexus. 

The smallest or renal splanchnic nerve arises from the 
last ganglion, and piercing the diaphragm, terminates in 
the renal plexus and lower part of the ccelic plexus. 



ANATOMY AND PHYSIOLOGY. 213 

A striking analogy appears to exist between the splanch- 
nic and the cardiac nerves. The cardiac nerves are three 
in number; they arise from the three cervical ganglia and 
are distributed to a large and important organ in the 
thoracic cavity. The splanchnic nerves, also three in 
number, are connected probably with all the dorsal ganglia, 
and are distributed to important organs in the abdominal 
cavity. 

The epigastric or solar plexus supplies all the viscera in 
the abdominal cavity. It consists of a great network of 
nerves and ganglia situated behind the stomach and in 
front of the aorta and crura of the diaphragm. It sur- 
rounds the coelic axis and root of the superior mesenteric 
artery, extending downward as low as the pancreas (XVI., 
3G) and outward to the suprarenal capsules (39). This 
plexus and the ganglia connected with it receive the great 
splanchnic nerve of both sides, part of the lesser splanch- 
nic nerve, and the termination of the right pneumogastric. 
It distributes filaments, which accompany, under the name 
of plexuses, all the branches from the front of the ab- 
dominal aorta. 

The semilunar ganglia of the solar plexus (LI., 7), two 
in number, one on each side, are the largest ganglia in the 
body. They are formed by the aggregation of smaller 
ganglia, having interspaces between them. They are situ- 
ated by the side of the cceliac axis and superior mesenteric 
artery, close to the suprarenal capsules; the one on the 
right side lies beneath the vena cava (XVI., 26) ; the upper 
part of each ganglion is joined by the greater and lesser 
splanchnic nerves, and to the inner side of each the 



214 A COMPEND OF 

branches of the solar plexus are connected. From the 
solar plexus are derived the following: 

The phrenic plexus, which accompanies the phrenic 
artery and with it is distributed to the diaphragm (27). 

The suprarenal plexus supplies the suprarenal gland 
(39). 

The renal plexus accompanies the renal artery (48, 49) 
and is distributed to the kidney. 

The spermatic plexus is distributed to the spermatic 
vessels. 

The cceliac plexus surrounds the cceliac axis and'divides 
into the 

Gastric plexus, distributed to the stomach (XIIL, 1); the 
hepatic plexus, to the liver (XVI., 28); and the splenic 
plexus, to the spleen (35). 

The superior mesenteric plexus surrounds the superior 
mesenteric artery, which it accompanies into the mesentery 
(42). 

The inferior mesenteric p 7 exus is derived from the left 
side of the aortic plexus.. It surrounds the inferior mes- 
enteric artery, and divides into a number of secondary 
plexuses which are distributed to the descending and sig- 
moid flexure of the colon and rectum (43). 

The Lumbar Portion of the Sympathetic is situated in 
front of the vertebral column, along the inner margin of 
the Psoas muscle (XIII., a). It consists usually of four 
ganglia, connected together by interganglionic cords. 
Some of the branches from these ganglia descend in front 
of the common iliac arteries, and join over the promontory 
of the sacrum, to form the hypogastric plexus (LI., 10). 



ANATOMY AND PHYSIOLOGY. 215 

The Pelvic Portion of the Sympathetic is situated in 
front of the sacrum, along the inner side of the anterior 
sacral foramina. It consists of four or five small ganglia 
on each side, connected together by interganglionic cords. 
Below, these cords converge and unite in front of the 
coccyx, by means of a small ganglion (ganglion impar). 

The hypogastric plexus supplies the viscera of the pel- 
vic cavity. It is situated in front of the promontory of 
the sacrum, between the two common iliac arteries (XVI., 
52, 53) and is formed by the union of numerous filaments, 
which descend on each side from the aortic plexus, from 
the lumbar ganglia, and from the first two sacral ganglia. 
This plexus bifurcates, below, into two lateral portions, 
which form the inferior hypogastric, or pelvic plexuses. 
These distribute branches to all the viscera of the pelvis. 



ORGANS OF SENSE. 

THE TONGUE. 

(XXXIII., LXXVI.) 

The Tongue is the organ of the special sense of taste. 
Its base, or root, is directed backward, and connected with 
the os hyoides by numerous muscles, with the epiglottis 
by three folds of membrane, which form the glosso-epi- 
glottic ligaments, and with the soft palate and pharynx by 
means of the anterior and posterior pillars of the faucos. 
The under surface is connected with the lower jaw by the 
Genio-hyo-glossi muscles; from its sides the mucous mem- 



2l6 A COMPEND OF 

brane is reflected to the inner surface of the gums; and 
in front a distinct fold of that membrane, the fraenum 
linguae, is formed beneath its under surface. 

The dorsum is the upper surface of the tongue, which is 
invested with mucous membrane and covered with papillae 
which are distinguished as simple, minimae, mediae, and 
maxima. The papillae apparently resemble in structure 
those of the cutis, consisting of a cone-shaped projection 
of homogeneous tissue, covered with a thick layer of 
squamous epithelium, and contain one or more capillary 
loops, among which nerves are distributed in great abun- 
dance. 

Besides the papillae, the mucous membrane of the tongue 
is provided with numerous follicles and glands. 

The tongue consists of two symmetrical halves, sepa- 
rated from each other in the middle line by a fibrous sep- 
tum. Each half is composed of muscular fibres arranged 
in various directions, containing much interposed fat and 
supplied by vessels and nerves: the entire organ is invested 
by mucous membrane and a submucous fibrous stratum. 

The fibrous septum consists of a vertical layer of fibrous 
tissue, extending throughout the entire length of the mid- 
dle line of the tongue, from the base to the apex. 

Each half of the tongue consists of extrinsic and in- 
trinsic muscles. 

The arteries of the tongue are derived from the lingual, 
the facial, and ascending pharyngeal. The nerves of the 
tongue are three in number in each half : the gustatory 
branch of the fifth, which is distributed to the papillae at 
the fore part and sides of the tongue; the lingual branch 



ANATOMY AND PHYSIOLOGY. 2\J 

of the glossopharyngeal, which is distributed to the mucous 
membrane at the base and side of the tongue and to the 
papilla 1 maxima*; and the hypoglossal nerve, which is dis- 
tributed to the muscular substance of the tongue. The 
two former are nerves of common sensation and taste; the 
latter is the motor nerve of the tongue. 

THE NOSE. 

The Nose is the special organ of the sense of smell. By 
means of the peculiar properties of its nerves it protects 
the lungs from the inhalation of deleterious gases and 
assists the organ of taste in discriminating the properties 
of food. The organ of smell consists of two parts — one 
external, the nose; the other internal, the nasal fossae. 

The base of the nose presents two elliptical orifices, the 
nostrils, separated from each other by an antero-posterior 
septum, the column a. The margins of these orifices are 
provided with a number of stiff hairs, or vibrissas, which 
arrest the passage of foreign substances carried with the 
current of air intended for respiration. The lateral sur- 
faces of the nose form by their union the dorsum, the 
direction of which varies considerably in different indi- 
viduals. The dorsum terminates below in a rounded emi- 
nence, the lobe of the nose. 

The nose is composed of a framework of bones and car- 
tilages, the latter being slightly acted upon by certain 
muscles. It is covered externally by the integument, in- 
ternally by mucous membrane, and supplied with vessels 
and nerves. 



2lS A COMPEND OF 

The bony framework occupies the upper part of the 
organ; it consists of the nasal bones and the nasal proc- 
esses of the superior maxillary. 

The cartilaginous framework consists of five pieces, the 
two upper and the two lower lateral cartilages and the 
cartilage of the septum. 

These various cartilages are connected to each other 
and to the bones by a tough fibrous membrane, the peri- 
chondrium, which allows the utmost facility of movement 
between them. 

The muscles of the nose are situated immediately beneath 
the integument: they are (on each side) the Pyramidalis 
nasi, the Levator labii superioris alseque nasi, the Dilator 
nasi-, anterior and posterior, the Compressor nasi, the Com- 
pressor narium minor, and the Depressor alge nasi. 

The mucous membrane lining the interior of the nose 
is continuous with the skin externally and with that which 
lines the nasal fossa within. 

The arteries of the nose are the lateralis nasi, from the 
facial, and the nasal artery of the septum, from the supe- 
rior coronary, which supplies the alse and septum; the 
sides and dorsum being supplied from the nasal branch of 
the ophthalmic and the infraorbital. 

The veins of the nose terminate in the facial and oph- 
thalmic. 

The nerves of the nose are branches from the facial, in- 
fraorbital, and infratrochlear, and a filament from the nasal 
branch of the ophthalmic. • 



ANATOMY AND PHYSIOLOGY, 2IQ 

NASAL FOSSJE. 
(XXXIIL, 1.) 

The Nasal Fosses are two large irregular cavities situated 
i the middle line of the face, extending from the base of 
be cranium to the roof of the mouth, and separated from 
ach other by a thin vertical septum. They communicate 
y two large apertures, the anterior nares, with the front 
f the face, and with the pharynx behind by the two pos- 
srior nares. Each nasal fossa communicates with four 
muses, the frontal above, the sphenoidal behind, and the 
laxillary and ethmoidal on either side. Each fossa also 
ommunicates with four cavities — with the orbit by the 
ichrymal canal, with the mouth by the anterior palatine 
anal, with the cranium by the olfactory foramina, and 
ith the spheno-maxillary fossa by the spheiio-palatine 
3ramen; and they occasionally communicate with each 
ther by an aperture in the septum. The bones entering 
lto their formation are fourteen in number: three of the 
ranium, the frontal, sphenoid, and ethmoid, and all the 
ones of the face excepting the malar and lower jaws. 
lach cavity is bounded by a roof, a floor, an inner and an 
uter wall. 

The mucous membrane lining the nasal fossae is called 
le pituitary, from the nature of its secretion. It is inti- 
lately adherent to the periosteum, or perichondrium, over 
hich it lies. It is continuous externally with the skin 
irough the anterior nares, and with the mucous mem- 
rane of the pharynx through the posterior nares. It also 



220 A COMPEND OF 

lines the various passages opening into the nares including 
the Eustachian tube. 

The arteries of the nasal fosses are the anterior and pos- 
terior ethmoidal, from the ophthalmic, which supply the 
ethmoidal cells, frontal sinuses, and roof of the nose; the 
sphenopalatine, from the internal maxillary, which sup- 
plies the lining membrane of the antrum. The ramifica- 
tions of these vessels form a close plexiform network be- 
neath and in the substance of the mucous membrane. 

The veins of the nasal fossce form a close network be- 
neath the mucous membrane. This network connects itself 
by numerous branches with the numerous veins internal 
and external that terminate in the jugulars in the neck. 

The nerves are the olfactory, the nasal branch of the 
ophthalmic, filaments from the anterior dental branch of 
the superior maxillary, the Vidian, naso-palatine, descend- 
ing anterior palatine, and spheno-palatine branches of 
Meckel's ganglion. 

The olfactory (XL., 1), the special nerve of the sense of 
smell, originating in the olfactory bulb beneath the anterior 
lobe of the brain, is distributed over the upper third of the 
septum and over the surface of the superior and middle 
spongy bones. 

« 
THE EYE. 

(LXVIII.) 

The Eyeball is contained in the cavity of the orbit. In 
this situation it is securely protected from injury, while its 
position is such as to insure the most extensive range of 



ANATOMY AND PHYSIOLOGY. 221 

sight. It is acted upon by numerous muscles, by which it 
is capable of being directed to any part, supplied by ves- 
sels and nerves, and is additionally protected in front by 
several appendages, such as the eyebrow, eyelids, etc. 

The eyeball is spherical in form, having the segment of 
a smaller sphere engrafted upon its anterior part. The 
segment of the larger sphere, which forms about five-sixths 
of the globe, is opaque and formed by the sclerotic, the 
tunic of protection to the eyeball; the white of the eye is 
the anterior section of this tunic ; the smaller sphere, which 
forms the remaining sixth, is transparent, and formed by 
the cornea. The axes of the eyeballs are nearly parallel, 
and do not correspond to the axes of the orbits, which are 
directed outward. The optic nerves follow the direction 
of the axes of the orbits, and enter the eyeball a little to 
their inner or nasal side. The eyeball is composed of sev- 
eral investing tunics and of solid and fluid refracting 
media called humors. 

The tunics are three in number : 1. Sclerotic (LXXIL, 
11) and Cornea (5). 2. Choroid (10, 11), Iris, and Ciliary 
Processes (3). 3. Ketina (9). 

The refracting media, or humors, are also three : Aque- 
ous, Crystalline (lens) and Capsule (2), and Vitreous (1). 

The Cornea is the projecting transparent part of the 
external tunic of the eyeball. It is convex anteriorly, and 
projects forward from the sclerotic in the same manner 
that a watch-glass does from its case. Its degree of curva- 
ture varies in different individuals and in the same indi- 
vidual at different periods of life, it being more prominent 
in youth than in advanced life, when it becomes flattened. 



222 A COMPEND OF 

Its anterior surface is kept polished and brilliant by the 
watery lachrymal secretion distributed over it by the 
movements of the eyeball and lids. 

There are no blood-vessels in the cornea, but nerves are 
abundant, derived from the ciliary nerves. 

The second tunic is formed by the choroid behind, the 
iris and ciliary processes in front, and by the ciliary liga- 
ment and Ciliary muscle at the point of junction of the 
sclerotic and cornea. 

The Iris (LXVIIL, 2) has received its name from its 
various colors in different individuals. It is a thin, circu- 
lar-shaped, contractile curtain, suspended in the aqueous 
humor behind the cornea and in front of the crystalline 
lens, being perforated at the nasal side of its centre by a 
circular aperture, the pupil (1), for the transmission of 
light. By its circumference it is intimately connected 
with the choroid ; externally to this is the ciliary ligament, 
by which it is connected to the sclerotic and cornea; its 
inner edge forms the margin of the pupil; its surfaces are 
flattened and look forward and backward, the anterior 
surface toward the cornea, the posterior toward the ciliary 
processes and the lens. The circumference of the iris is 
connected to the cornea. The posterior surface of the iris 
is of a dark purple, as is also the interior of the choroid. 
The iris is composed of a fibrous stroma, muscular fibres, 
and pigment-cells. 

The muscular fibres of the iris are arranged as both 
sphincter and dilator muscles, for the expansion and con- 
traction of the pupil. 

The Ciliary muscle is the chief agent in adjusting the 



ANATOMY AND PHYSIOLOGY. 223 

eye to the vision of near objects. This muscle is com- 
posed of unsfcriped fibres, which arise at the junction of 
the sclerotic and cornea, and thence diverge in a radiating 
direction, outward and backward, to be inserted into the 
external surface of the choroid where it passes into the 
folds of the ciliary processes. At the anterior and inner 
part of the muscle there are also bundles of circular fibres, 
parallel with the margin of the cornea. The muscle is 
thus composed of two parts, namely, an internal circular 
and an external radiating portion, the fibres of which are 
more or less interwoven with each other at its inner edge. 

The Choroid coat is a vascular and pigmentary mem- 
brane lining the inner surface of the sclerotic, and present- 
ing anteriorly a thickened portion, the "ciliary body." 
The inner part of the ciliary body is thrown into radiating 
folds, the " ciliary processes, which surround the borders 
of the crystalline lens. At its anterior part the choroid 
is separated from the sclerotic by the ciliary muscle. 

Aqueous and Vitreous Body (LXXIL). — The cavity of 
the eyeball is divided by the transverse partition of the 
iris into two portions — an anterior and posterior. The 
portion in front of the iris, called the " anterior chamber," 
is filled with a colorless, transparent watery fluid, the 
aqueous humor. This fluid serves to maintain the inter- 
nal tension of the eyeball, and to allow the changes in the 
iris and crystalline lens without affecting the external 
configuration of the cornea. The posterior and larger por- 
tion of the cavity of the eyeball is filled by a semi-fluid 
gelatinous substance, the vitreous body, so called from its 
transparent and glossy appearance. Its refractive power 



224 A COMPEND OF 

does not differ greatly from that of water. It distends the 
greater part of the cavity of the sclerotic, supports the . 
retina, which lies upon its surface, and preserves the sphe- 
roidal form of the eyeball. 

The vitreous body is enveloped by an exceedingly thin, 
colorless membrane, for the most part without definite 
structure, called the u hyaloid membrane/' It extends over 
the posterior and middle portions of the vitreous body to 
a zone corresponding with the ciliary body of the choroid. 
Here it becomes thicker and divides into two layers. The 
lens is thus suspended from all sides by a double layer 
derived from this membrane. 

Crystalline Lens (LXXIL, 2). — The lens is a transparent, 
refractive body, with convex anterior and posterior sur- 
faces, placed directly behind the pupil, where it is retained 
in position by the counterbalancing pressure of the aque- 
ous humor and vitreous body and by the suspensory layers 
of the hyaloid membrane (10). Being double convex in 
form it acts as a converging lens to change the direction 
of rays passing through it and bring them to a focus be- 
hind its posterior surface. The amount of convergence 
thus effected by a refractive lens depends on the substance 
of which it is composed and the curvature of its surfaces. 
The stronger the curvatures, the greater their refractive 
power for luminous rays. In the lens of the eye the two 
surfaces are different in curvature; the anterior being com- 
paratively flat, the posterior more convex. 

This makes the crystalline lens the strongest refracting 
body in the eyeball, and by its aid parallel or diverging 
rays are brought to a focus at the retina (9). This effect, 



ANATOMY AND PHYSIOLOGY. 22$ 

however, is not due entirely to the lens, as the convexity 
of the cornea, the spherical form of the eyeball, and the 
adjustment of the iris are all accessories in producing this 
effect. The mechanism of the photographic camera, with 
its lenses, diaphragms, and plates, fairly illustrates the 
structure and functions of the eye. Like the plate in the 
camera, the retina receives the image reversed in its con- 
tour; but in its transmission through the optic nerve and 
the optic commissure to the seat of intelligence in the 
brain, the image is again reversed and the mind takes 
cognizance as we see it. 

Retina (9). — The retina is the most essential part of the 
organ of vision, since it is the only one sensitive to light. 
It forms a nearly transparent membrane, composed of ner- 
vous elements, situated between the inner surface of the 
choroid and the outer surface of the hyaloid membrane, 
and extending from the entrance of the optic nerve to the 
commencement of the ciliary body. 

APPENDAGES OF THE EYE. 

The appendages of the eye include the eyebrows, eyelids, 
the conjunctiva, and the lachrymal apparatus, viz., the 
lachrymal gland, the lachrymal sac, and the nasal duct. 

The eyebrows in structure consist of thickened integu- 
ment, connected beneath with the Orbicularis palpebra- 
rum, Corrugator supercilii, and Occipito-frontalis muscles. 
These muscles control, to a certain extent, the amount of 
light admitted into the eye. 

The eyelids are two thin, movable folds, placed in front 
r 5 



226 A COMPEND OF 

of the eye, protecting it from injury by their closure. The 
upper lid is the larger and the more movable of the two, 
and is furnished with a separate elevator muscle, the Leva- 
tor palpebrae superioris. When the eyelids are opened 
an elliptical space (fissura palpebrarum) is left between 
their margins, the angles of which correspond to the junc- 
tion of the upper and lower lids, and are called canthi. 

The outer canthus is more acute than the inner, and the 
lids here lie in close contact with the globe; but the inner 
canthus is prolonged for a short distance inward toward 
the nose, and the two lids are separated by a triangular 
space, the lacus lachrymalis. At the commencement of the 
lacus lachrymalis, on the margin of each eyelid, is a small 
conical elevation, the lachrymal papilla or tubercle, the 
apex of which is pierced by a small orifice, the punctum 
lachrymale (LXIX., 7), the commencement of the lachrymal 
canal. The eyelids are composed of the following struc- 
tures, taken in their order from without inward : Integu- 
ment, areolar tissue, fibres of the Orbicularis muscle, tarsal 
cartilage, fibrous membrane, Meibomian glands, and con- 
junctiva. The upper lid has in addition the aponeurosis 
of the Levator palpebras. 

The integument is extremely thin, and continuous at the 
margin of the lids with the conjunctiva. 

The Meibomiam glands are situated upon the inner sur- 
face of the eyelids, between the tarsal cartilages and con- 
junctiva, and may be distinctly seen through the mucous 
membrane on everting the eyelids, presenting the appear- 
ance of parallel strings of pearls. Their ducts open on 
the free margin of the lids by minute foramina (LXIX., 3), 



ANATOMY AND PHYSIOLOGY. 227 

which correspond in number to the follicles. The secre- 
tion of these glands is sebaceous matter and its use is to 
prevent adhesion of the eyelids. 

The conjunctiva is the mucous membrane of the eye. 
It lines the inner surface of the eyelids and is reflected 
over the fore part of the sclerotic and cornea. In each of 
these situations its structure presents some peculiarities. 



LACHRYMAL APPARATUS. 
(LXIX.) 

The Lachrymal Apparatus consists of the lachrymal 
gland (1), which secretes the tears, and its excretory ducts, 
which convey the fluid to the surface of the eye. This 
fluid is carried away by the lachrymal canals into the 
lachrymal sac (8) and along the nasal duct into the cavity 
of the nose. 

The lachrymal gland is lodged in a depression at the 
outer angle of the orbit, on the inner side of the external 
angular process of the frontal bone. It is of an oval form, 
about the size and shape of an almond. It is in contact 
with the periosteum of the orbit, and rests upon the con- 
vexity of the eyeball and upon the Superior and External 
recti muscles. In structure and general appearance the 
lachrymal resembles the salivary glands. Its ducts, about 
seven in number, open by a series of minute orifices on the 
upper and outer half of the conjunctiva, near its reflection 
on to the globe. 

The lachrymal canals commence at the minute orifices, 



228 A COMPEND OF 

puncta lachrymalia (LXIX., 7), seen on the margin of the 
eyelids at the outer extremity of the lacus lachrymalis. They 
commence on the summit of a slightly-elevated papilla, the 
papilla lachrymalis, and lead into minute canals, the ca- 
naliculi, which proceed inward to terminate in the lachry- 
mal sac (8). 

The lachrymal sac is the upper dilated extremity of the 
nasal duct, and is lodged in a deep groove formed by the 
lachrymal bone and nasal process of the superior maxil- 
lary. 

The nasal duct is a membranous canal, about three- 
quarters of an inch in length, which extends from the 
lower part of the lachrymal sac to the inferior meatus of 
the nose, where it terminates by a somewhat expanded 
orifice, provided with an imperfect valve formed by the 
mucous membrane. It is lined by mucous membrane 
which is continuous below with the pituitary lining of the 
nose (LXVIIL, LXVIX., LXX., LXXL, LXXIL). 

SENSE OF HEARING. 

By the sense of hearing we receive the impressions of 
sound and appreciate their intensity, their higher or 
lower notes, and their quality — that is, the different charac- 
ter of sounds of similar pitch and intensity produced by 
different means. 

Organ. of Hearing (LXXV.). — The organ of hearing con- 
sists of, first, the external ear (1), a trumpet-shaped expan- 
sion which collects the sonorous impulses coming from 
various quarters and conducts them into its tubular con- 



ANATOMY AND PHYSIOLOGY. 229 

» 
tinuation, the external auditory meatus (2); secondly, a 

membranous sheet or drum-head, the membrana tympani 
(3), stretched across the auditory meatus, by which the 
sound is received and transmitted, through the chain of 
bones in the tympanum, to the labyrinth, or internal ear; 
a cavity in the petrous portion of the temporal bone con- 
taining various membranous sacs and canals, upon which 
are distributed the filaments of the auditory nerve. 

Thus the terminal expansions of the auditory nerve, 
deeply concealed in their bony cavities and sustained by 
the surrounding fluids, while protected from all other me- 
chanical impressions, are so placed as to receive the im- 
pulse of sound. 

External Ear. — The external ear is a cartilaginous frame- 
work, covered with integument, and more or less movable 
by various muscles, which turn it in various directions. 
In man these muscles are nearly inactive, though in ex- 
ceptional cases they can produce a partial sliding or rotary 
movement of the ear. 

The Membrana Tympani and Chain of Bones. The 
membrana tympani is a circular fibrous sheet, very thin 
but quite strong, consisting of circular and radiating tendi- 
nous fibres, with a trace of intermingled elastic tissue. 

In its natural position the membrane is drawn inward, 
by its attachment to the malleus, in such a way as to pre- 
sent a funnel-shaped depression, the deepest point of 
which corresponds to the end of the handle of the malleus. 
From its thinness and tension, and from its position at 
the bottom of the external auditory meatus, it enters into 
vibration, under the impulse of sounds from the exterior, 



23O A COMPEND OF 

and communicates its movement to the handle of the mal- 
leus at its inner surface. 

The chain of bones consists of three ossicles, articulated 
with each other by their extremities, and forming a zigzag 
line of jointed levers across the cavity of the tympanum 
(LXXV., 3). They are known respectively, from their 
configuration, as the " malleus," " incus," and " stapes," or 
the hammer, the anvil, and the stirrup. 

These bones are so articulated that they regulate the 
condition of the tympanic membrane in the reception of 
sound. 

The cavity of the tympanum (3) is an irregularly-shaped 
space, across which the vibrations received by the mem- 
brana tympani are transmitted by the chain of bones. In 
their natural position and with their tendinous connections 
undisturbed, these bones are in such close connection with 
each other that they vibrate as a single body. 

The cavity of the tympanum communicates with the 
pharynx by the Eustachian tube (4). The existence of this 
canal secures equality of atmospheric pressure on both 
sides of the membrane, a condition essential to its free 
vibration under sonorous impulses. Although the walls of. 
the Eustachian tube are habitually in contact with each 
other, they readily yield to atmospheric pressure in either 
direction and thus re-establish the equilibrium between 
the outer air and the cavity of the tympanum. 

Labyrinth (LXXIV., LXXV.).— The internal ear, or 
labyrinth, so called from the complicated extension of its 
cavities, is situated in the petrous portion of the temporal 
bone. Its divisions are the vestibule and semicircular 



ANATOMY AND PHYSIOLOGY. 23 I 

canals (LXXIV., 1, 2, 3), which constitute its most essen- 
tial parts; and the cochlea (5), which is a more highly- 
developed portion. 

The vestibule is so called because its cavity is that into 
which the fenestra ovalis immediately opens, and which 
leads to the semicircular canals and cochlea. It has an 
ovoid form, and presents on the side toward the tym- 
panum two openings, namely: 1. The fenestra ovalis, cor- 
responding in form to the base of the stapes, which nearly 
fills it and which is adherent to the internal periosteum of 
the labyrinth. 2. The fenestra rotunda, of smaller size 
and closed by a fibrous membrane. The posterior portion 
of the vestibule gives origin to the three semicircular 
canals, namely: 1. The superior vertical canal with its 
plane lying across the longitudinal axis of the petrous 
bone. 2. The inferior vertical canal, the plane of which is 
parallel with the median surface of the petrous bone. 3. 
The horizontal canal, lying across the axis of the petrous 
bone in a horizontal plane. Each semicircular canal opens 
into the vestibule by two orifices, one at each end; except 
that the two vertical canals unite at one extremity into 
an orifice common to both. Each canal is enlarged at one 
extremity, where it joins the vestibule, into a rounded di- 
latation. 

This part of the bony labyrinth contains a colorless fluid 
— the perilymph, and, in addition, a membranous sac also 
filled, with fluid, which, by its prolongations, repeats the 
form of the vestibule and semicircular canals. This sac, 
with its extension in the cochlea, constitutes the membran- 
ous labyrinth. It forms the most important part of the 



232 A COMPEND OF 

internal ear, since in its walls the filaments of the auditory 
nerve have their terminal distribution. 

In the vestibule the membranous sac is divided into two 
parts by a transverse partition. One of these, the smaller 
of the two, is the sacculus, a spherical vesicle occupying 
the anterior and inferior portion of the vestibule, and com- 
municating by a narrow canal with the ductus cochlearis 
of the cochlea. The other, or larger sac, is the utricle, of 
ellipsoid form. The utricle and the membranous semi- 
circular canals communicate with each other in the same 
way as the bony cavities in which they are lodged; and 
each membranous canal presents, at one extremity, a 
rounded dilatation, known as the ampulla (LXXIV., 6, 9, 
10). The sacculus and utricle together occupy about two- 
thirds of the cavity of the vestibule, and are so placed that 
neither touches the base of the stapes at the fenestra ovalis, 
from which they are separated by an appreciable layer of 
fluid. Thus sonorous impulses reach the membranous 
labyrinth, not directly from the stapes, but through the 
intermediate medium of the perilymph. 

The main point of interest in regard to the membranous 
labyrinth relates to the distribution and termination of 
the auditory nerve. 

The nerve sends to the. vestibule two branches ; one dis- 
tributed to the sacculus, the other, to the utricle and am- 
pullae. The mode of termination of the nerve fibres in 
both divisions is essentially the same. They are not dis- 
tributed generally over the membrane, but terminate in 
well-defined spots, characterized by a thickening of the 
membranous wall, and by a peculiar form of epithelium 



ANATOMY AND PHYSIOLOGY. 233 

provided with stiff, pointed cilia — the so-called auditory 

hair*. 

A remarkable feature connected with the auditory spots 
of the sacculus and utricle is the so-called otoconia, or ear 
sand. This consists of calcareous grains imbedded in a 
gelatinous material and forming a white, chalky-looking 
layer immediately over the auditory spot. The grains are 
rounded, elongated, or prismatic and crystalline in form. 
Their exact office is unknown, but it is evident, from their 
constant existence in this situation, that they have some 
important relation to the sense of hearing; they are pul- 
verulent. 

Physiological Action of the Membranous Ldbyrin th. The 
sacculus and utricle are membranous formations, sus- 
pended in the fluid of the vestibule and supplied by fibres 
of the auditory nerve. They are the essential parts in the 
auditory apparatus for the reception of sonorous impres- 
sions. The sound communicated to the membrana tympani 
is thence transmitted through the malleus, incus, and stapes. 
From the base of the stap>es it passes to the perilymph of 
the vestibular cavity; thence through the wall of the mem- 
branous sac to the endolymph or fluid in its interior; and 
through this fluid to the nervous terminations at the audi- 
tory spot. It is thus that sounds coming from without 
finally produce their impression on the internal ear. 

Office of the Semicircular Canals. — An essential point in 
the structure of these canals is that they are destitute of 
nerve fibres, and consequently wanting in sensibility. The 
only nervous distribution connected with them is that to 
the ampullse at their extremities, but no fibres extend to 



234 A COMPEND OF 

the canals themselves. Their function must, therefore, in 
all probability be of a mechanical or physical nature. It 
is supposed that this has some relation to the sense of 
equilibrium in the motions of the head. 

Cochlea (LXXIV., 8). — The cochlea, so called from its 
resemblance to a snail shell, is a spiral bony canal making 
two or three turns about a central axis, with its apex di- 
rected forward, downward, and outward. It is divided 
longitudinally by a thin, bony partition, the spiral lamina, 
which winds round its axis, following the spiral turns, but 
presenting externally a free border. 

From this border a fibrous membrane, the membrana 
basilaris, extends outward to the external wall of the cav- 
ity; thus forming two parallel passages, one above the 
other. The upper passage, which communicates at its 
base with the vestibule, is the scala vestibuli. The lower 
reaches to the fenestra rotunda, where the membrane, 
stretched across this opening, separates its cavity from 
that of the tympanum; it is accordingly known as the 
scala tympani. At the apex of the cochlea a minute orifice 
of communication between the two canals has been de- 
scribed by some writers and doubted by others. 

The ductus cochlearis may be considered as a tubular 
prolongation of the sacculus, rolled upon itself in a spiral 
form and held in position by the adjacent parts of the 
cochlea. Like the rest of the membranous labyrinth, it is 
filled with a watery fluid and surrounded by the peri- 
lymph, except where it is adherent to the walls of its bony 
cavity. 

Organ of Corti.-^The ductus cochlearis is lined with pave-* 



ANATOMY AND PHYSIOLOGY. 235 

ment epithelium, except along the middle of the membrana 
basilaris. Here there is a continuous elevated ridge, four 
or five times thicker than the epithelium elsewhere, con- 
sisting of enlarged and modified epithelium cells, and con- 
.taining the terminal fibres of the auditory nerve. This 
body is named the organ of Corti, from the observer by 
whom it was first described. It is justly considered as the 
most remarkable structure in the internal ear, although in 
its essential features analogous to the auditory spots of the 
sacculus and utricle. 

The organ of Corti rests upon the upper surface of the 
membrana basilaris. Its framework consists of a series of 
elongated, rafter-like bodies, arranged in two rows, inter- 
nal and external. These bodies, the inner and outer 
" fibres of Corti/' are separated below, where they rest upon 
the membrana basilaris, by a considerable interval ; but 
their upper extremities lie in contact with each other, thus 
forming a roof-like connection, the "arch of Corti/' Near 
the arch the epithelium cells increase in length ; and at 
its inner border there is a row of cells nearly as long as the 
innermost fibres of Corti, and in a similar leaning position, 
bearing upon their upper extremity a tuft of rigid hairs 
or cilia. On the outer border of the arch there are three 
such rows of hair cells, and in every instance the cilia 
project through openings in a sort of fenestrated cuticle 
extending above the cells, inward and outward, from the 
middle of the arch. 

The fibres of the cochlear branch of the auditory nerve 
are distributed to the organ of Corti, and here is evidently 
the especial apparatus of auditory sensibility. 



236 A COMPEND OF ANATOMY AND PHYSIOLOGY. 

Physiological Action of the Cochlea. — The cochlea, no 
doubt, as compared with the rest of the internal ear, serves 
for the precise discrimination of minute variations in 
sound. Some physiologists suppose that its structure 
shows a similarity to the mechanism of stringed musical 
instruments, and that the ability to appreciate musical 
sounds is therefore located here. 



GLOSSARY. 



Abdomen. The cavity bounded by the diaphragm, pelvis, 
lumbar vertebrae and muscular expansions. 

Abdominal. Belonging to the abdomen. 

Abductor. A muscle which moves certain parts by separating 
them from the axis of the body. 

Acromial. Pertaining to the acromion. 

Acromion. The process on the spine of the scapula articulat- 
ing with the clavicle. 

Adductors. Muscles which draw the parts toward the axis of 
the body. 

Adipose. That which relates to fat. 

Acetabulum. The cavity at the side of the pelvis with which 
the head of the femur articulates to form the hip- joint. 

Alimentary. Relating to nutriment. 

Alveolar. From alveoli, the sockets of the teeth. 

Anastomosis. Communication of vessels and nerves with one 
another of the same kind. 

Aneurism. An excrescence sometimes formed on the surface 
of blood-vessels. 

Angiology. The science which treats of the heart, blood- 
vessels, and lymphatics. 

Anterior. The parts in front or before. 

Aorta. The great central arterial trunk of the body. 

Aortic. Pertaining to the aorta. 

Aponeurosis. White shining membranes composed of inter- 
laced fibres, attached to and accessory to the muscles. 

Apex. The point or extremity of a part. 



238 A COMPEND OF 

Appendix auriculae. Conical muscular pouches attached to 
each of the auricles of the heart. 

Aqueous. Of the nature of water — watery. 

Articulate. To form a joint. 

Articular. Pertaining to a joint. 

Areolar. From areola, the interstices between the fibres 
composing organs, or between vessels which interlace with 
each other. 

Arteriae receptaculi. Numerous small vessels given off from 
the cavernous portion of the internal carotid artery. 

Arteria innominata (innominate artery). The large artery 
arising from the right side of the arch of the aorta and 
sending its branches to the right side of the head and right 
arm. 

Arterialized (hsematosis). The transformation of the venous 
blood and chyle into arterial blood. 

Arachnoid membrane. The serous membrane that envelops 
the brain, lying between the dura mater and pia mater. 

Astragalus. The largest of the tarsal bones forming the 
ankle-joint. 

Ascending or inferior vena cava. The large venous trunk 
which accompanies the abdominal aorta and which re- 
ceives the blood from the lower extremities and from all 
the portions of the body below the heart. 

Auditory. Pertaining to the hearing. 

Auricle, or pinna. The outer portion of the external ear. Also 
the name of the two upper cavities of the heart. 

Auricularis — Auricular. That which belongs to the ear, es- 
pecially the external ear. 

Auriculo-ventricular. The connection between an auricle and 
ventricle. 

Axilla.. The cavity beneath the junction of the arm with the 
shoulder — the arm-pit. 

Axillary. Belonging to the axilla. 

Azygos veins. Supply the place of the vena cava in the thorax 



ANATOMY AND physiology. 239 

and form connection between the superior and inferior 
vena cava. 

Base. The broad expanded portion of parts or organs. 

Bifurcation. Dividing into two branches. 

Biceps. The long muscle extending from the shoulder to the 
elbow-joint on the front of the arm. 

Bronchus. The system of air- tubes that issue from the bifur- 
cation of the trachea or windpipe, and are distributed 
through the substance of the lungs. 

Brachial. Belonging to the upper portion of the arm. 

Brevis. Short. 

Buccinator. A muscle in the substance of the side of the face. 

Carpus. The combination of bones in the wrist-joint. 

Cancellous — cancelli — cancellated. Re f er to the spongy texture 
of bone, consisting of numerous cells communicating with 
each other. 

Cartilage. The gristly substance connected with many por- 
tions of the skeleton. 

Coracoid. A short thick process situated at the anterior part 
of the upper margin of the scapula. 

Carpi ulnaris. Connected with the ulnar side of the carpus. 

Capillary vessels and plexuses. The extreme radicals of the 
arteries and veins, which together constitute the capillary, 
intermediate, and peripheral vascular system. 

Capsules. Organs over or covering other organs, as the supra- 
renal capsules. 

Carotid arteries. The large arteries in the neck whose 
branches carry the blood to the head. 

Costo-xiphoid articulation. The union of the costal cartilages 
with the xiphoid or ensiform appendix. 

Cavities. Hollow places for the reception of organs. 

Cardiac. Belonging to or relating to the heart. 

Calcaneum, or os calcis. The large bone at the heel of the 
foot to which the tendo Achillis is attached. 

Cervical. Related to the neck. 



240 A COMPEND OF 

Cell — cellule. A small cavity. The whole organized body is 
composed of various sets of these with different endow- 
ments, connected with absorption, nutrition, and secretion 
wherever selection or elaboration has to be effected. 

Cellular. Composed of cells. 

Cerebro-spinal center, or axis. The brain and spinal cord 
in combination. 

Cerebellum. The lower posterior division of the brain. 

Cerebrum. The larger, upper, anterior and posterior portion 
of the brain. 

Cerebral. Pertaining to or belonging to the brain. 

Cephalic. Relating to the head. 

Choroid. Several parts so called, but generally applied to the 
membrane of the eyeball, between the sclerotic and 
hyaloid membrane. 

Chyme. The condition of the food when it has passed the 
first stage of digestion in the stomach. 

Chyle. The completely digested alimentary substances in 
condition to be acted upon by the assimilating organs in 
the small intestine. 

Crystalline lens and capsule. The organ immediately behind 
the iris and pupil in the eye, by which images are formed 
on the retina as we see them. 

Ciliated epithelium. Provided with cilia or hair-like sub- 
stances similar to the eyelashes. 

Ciliary processes. Triangular folds placed at the side of each 
other, radiating like a flower, lodged in depressions at the 
anterior part of the vitreous humor in the eye. 

Clavicle. The long bone extending from the top of the sternum 
to the head of the humerus, commonly called the collar- 
bone. 

Coccyx. The lower bony extremity of the sacrum. 

Coronal. Pertaining to the top of the head. 

Condyles. Articular eminences, round in one direction and 
flat in the other, found at certain joints. 



ANATOMY AND PHYSIOLOGY. 24I 

Condyloid. Having the form of a condyle. 

Corium. The cutis vera or thickest part of the human skin — 
the true skin. 

Commissure. A point of union between two parts. 

Convolutions. The rolling of parts upon themselves, princi- 
pally employed to designate the structures of the brain 
and intestines. 

Corpus callosum. The commissure uniting the two hemi- 
spheres of the brain. 

Corpora albicantia. Two small bodies in the base of the 
brain immediately behind the tuber cinereum. 

Coeliac. Relating to the cavity of the abdomen. 

Cordiform. Heart-shaped tendon of the diaphragm. A thin 
tendinous aponeurosis at the centre of the vault immedi- 
ately below the pericardium. 

Corrugator supercilii. A muscle in the eyebrows that wrinkles 
the forehead. 

Communicating. Passing from one to another. Somewhat 
similar to anastomosis or inosculate. 

Coronary. Resembling a crown. A name designating numer- 
ous blood-vessels, nerves, ligaments, and tendons in the 
region of the heart and stomach. 

Conus arteriosus. The portion of the right ventricle of the 
heart from which the pulmonary artery proceeds. 

Cornea. The hard, transparent projection like a watch-glass 
on the front of the eyeball. 

Coronoid process. An eminence on the upper and front part 
of the ulna, 

Corpora arantia. A small projecting fibrocartilaginous nodule 
connected with the semilunar valves of the heart. A 
tooth-like prominence. 

Cochlea. The anterior part of the bony labyrinth of the ear, 
about a quarter of an inch in length and breadth. 

Crest of the ilium. The upper edge of the back and sides of 
the pelvis. 
16 



242 A COMPEND OF 

Cricoid. Having the form of a ring. One of the cartilages of 
the larynx. 

Crura. These form the oesophageal opening of the diaphragm, 
through which pass the oesophagus and pneumogastric 
nerve. 

Crura cerebri. Two thick cylindrical bundles of white matter 
in the base of the brain. 

Cranium. The skull. 

Crural. Belonging to the thigh or lower limb. 

Crural arch. Poupart's ligament. 

Cuboid. Having the form of a cube. The name of one of the 
tarsal or ankle bones. 

Cystic. Belonging to a cyst or cysts — especially to the gall- 
bladder. 

Deltoid. The large muscle covering the shoulder-joint. 

Derma. The cutis vera — true skin. 

Desiccate. To dry. 

Depressors. Several muscles which depress the parts to which 
they are attached. 

Descending, or Superior vena cava. The large vein that re- 
ceives the blood from the head and arms and passes it in- 
to the upper portion of the right auricle of the heart. 

Deglutition. The act by which food is passed from the mouth 
into the stomach. 

Dental. Pertaining to the teeth. 

Dextra. The right side. 

Digitations. Divisions into processes having the form of 
ringers. 

Diploe. The areolar structure separating the two tables of 
the skull. 

Diaphragm. The thin muscular expansion dividing the 
thoracic from the abdominal cavities. 

Diagnosis. The knowledge of diseases by their symptoms. 

Dorsal. Pertaining to the dorsum or the back part. 

Ductus communis choledochus. The common excretory duct 



ANATOMY AND PHYSIOLOGY. 243 

of the liver and gall-bladder, by which their secretions 
are carried to the duodenum. 

Duodenum. The upper and largest portion of the small intes- 
tine, called also the second stomach. 

Dura mater. The lining membrane of the cranium, and the 
outermost of the three membranes that envelop the brain. 

Diaphanous. Transparent. 

Ensiform appendix cartilage. The extreme lower portion of 
the sternum. 

Encephalon. The brain, sometimes including the spinal cord. 

Endocardium. The membrane that lines the interior of the 
heart. 

Epidermis. The cuticle — scarf skin. 

Epithelial. From epithelium, the thin layer of epidermis 
which covers parts deprived of derma within the body. 

Epigastrium. The middle and upper portion of the abdomen. 

Epiploic. From epiploon, a prolongation of the peritoneum 
in the upper portion of the abdomen. 

Ethmoidal. Related to the ethmoid bone, one of the eight 
bones that compose the cranium. 

Eustachian. A tube extending from the tympanum to the 
upper part of the pharynx. 

Eustachian. A valve at the opening of the inferior vena cava 
into the right auricle of the heart. 

External lateral ligament. A short and narrow fibrous fas- 
ciculous, attached above to the external condyle of the 
humerus ; below to the orbicular ligament and into the 
outer margin of the ulna. 

External oblique. A broad, thin muscle at the side of the abdo- 
men extending from the lower ribs to the crest of the ilium. 

External. On the outer parts. 

External saphenous vein. One of the two large superficial 
venous trunks of the leg, originating in the foot and ex- 
tending up the outer and back part of the leg ; connects 
with the popliteal vein above the knee-joint. 



244 A COMPEND OF 

Extensors. Muscles whose function is to extend certain parts. 
Expiration. The act of expelling the air from the lungs. 
Excretory organs. Those charged with the office of excreting. 

The skin is of this class. 
Eascia. The aponeurotic expansions of muscles which bind 

parts together. Fascia lata, which invests the muscles of 

the thigh, is the most extensive in the body. 
Facet. A small circumscribed surface of a bone. 
Eauces. A region in the upper part of the pharynx. 
Facial. Pertaining to the face. 
Femur. The thigh bone. 

Fibrous. Composed of fibres or minute threads. 
Fibula. The external and smaller of the two bones of the leg 

below the knee-joint. 
Fibro-cartilage. Cartilage of fibrous texture. 
Fissure. A cleft or division between two parts. 
Flexors. Muscles that bend the members at their joints. 
Flexure. A curvature or bending of an organ. 
Foramen. A name given to openings for the passage of vessels 

and nerves. 
Foramen magnum. The large oval opening in the base of the 

skull through which the medulla oblongata and spinal 

cord pass down. 
Foramen of Winslow. This is a constriction of the general 

peritoneal cavity, caused by the gastric and hepatic arte- 
ries passing forward from the cceliac axis to reach their 

respective viscera. 
Fossa. A cavity of greater or less depth, the entrance to which 

is always larger than the base. 
Follicles. A name applied to the structure of various glands. 
Frsenum. A name given to several membranous folds which 

bridle and retain certain organs. 
Gastrocnemius. The large muscle covering the back part of 

the leg below the knee-joint. 
Ganglion. Small accessory nerve centres for the reception and 



ANATOMY AND PHYSIOLOGY. 245 

distribution of nervous cords within the body. These are 
mostly connected with the sympathetic system. 

Gastric. Related to or belonging to the stomach. 

Gelatin. The animal principle of glue, and one of the prin- 
cipal constituents of bones, ligaments, tendons, fascise, and 
connective tissues generally. 

Gladiolus. The middle and largest division of the sternum. 

Glenoid. The name of certain cavities in which joints are 
formed for considerable variety of motion. 

Gluteus (plural glutei) — maximus, medius, minimus. Three 
muscles on the back part of the thigh. 

Glosso. Pertaining to the tongue. 

Gracilis. One of the muscles of the thigh. 

Great sciatic nerve. The largest nerve in the body. It 
issues from the sacral plexus through the sacro-sciatic fo- 
ramen, and passes down the back of the thigh, distribut- 
ing its branches to the leg and foot. 

Gustatory. Pertaining to the sense of taste. 

Haversian. The nutritive canals of bones through which the 
blood flows. 

Hair-follicles. The minute sacs inclosing the roots of the hair, 
into which sebaceous glands discharge their secretions. 

Hard palate. This is the roof of the mouth and is continuous 
with the soft palate, which is a movable fold suspended 
from its posterior border and forming an incomplete sep- 
tum between the mouth and pharynx. 

Hamstrings. The tendons that connect the muscles of the 
thigh with the leg below the knee. 

Hepatic. Pertaining to the liver. 

Homogeneous. Of the same kind. 

Hypoglossal. The motor nerve of the tongue, originating in 
the medulla oblongata. 

Humors of the eye. The fluids within the eyeball. 

Ilium. The upper portion of the os innominatum, which 
forms the prominence of the hip. 



246 A COMPEND OF 

Ileum. The lower portion of the small intestine. 

Ileo. This prefix indicates some relation between the ileum 
and some other organ or organs. 

Ilio. This is a prefix indicating a relation to the ilium or 
upper portion of the pelvis. 

Iliac arteries. The two branches of the aorta formed by its 
bifurcation in the abdomen. 

Inosculate. To communicate with each other. Nearly synony- 
mous with Anastomose. 

Innominata. Nameless. 

Intervertebral. Between the vertebrae. 

Integument. The skin, including the cuticle, rete mucosum, 
and cutis vera. 

Interosseous. Between the bones. 

Internal malleolus. A process on the lower extremity of the 
tibia. External m., a similar process on the lower extrem- 
ity of the fibula. 

Interdigitating. Passing between the fingers. 

Inferior maxillary bone. The lower jaw. 

Infundibulum. A slender isthmus connecting the pituitary 
body to the base of the brain immediately behind the 
optic commissure. 

Inguinal glands. Those in the groin. 

Intercostal. Between the ribs. 

Intermuscular. Between the muscles. 

Incus. One of the bones of the ear. 

Infra-orbital. Within the orbit. 

Internodii. Parts of the fingers between the joints; pha- 
langes. 

Iris. The portion of the eye immediately behind the cornea 
and in front of the crystalline lens, pierced by the orifice 
called the pupil. 

Island of Reil. A triangular-shaped cluster of convolutions 
of the brain inclosed in the branches of the fissure of 
Sylvius, 



ANATOMY AND PHYSIOLOGY. 247 

Ischium. The lower portion of the pelvic bone perforated by 

the obturator foramen. 
Jejunum. The middle portion of the small intestine. 
Jugulars. The large veins in the neck receiving the blood 

from the head to be conveyed to the heart and lungs. 
Lachrymal. Of the nature of or pertaining to the tears. 
Levators. Muscles that elevate the parts. 
Lambdoidal suture. The connection between the occipital and 

parietal bones of the skull. 
Lamina cinerea. A thin layer of gray substance which forms 

the anterior part of the inferior boundary of the third 

ventricle of the brain. 
Laryngeal. Connected with or pertaining to the larynx. 
Lateralis nasi. Side of the nose. 
Labial. Pertaining to or belonging to the lip. 
Labyrinth. The series of cavities in the petrous bone of the 

ear connecting the tympanum with the auditory nerve. 
Laminae. A name applied to various thin membranous 

structures in delicate organs of the body, as the eye and 

ear. 
Linea ileo-pectinea. The projecting line or ridge of the ilium 

and pubes which forms part of the brim of the pelvis. 
Linea alba. A tendinous, strong, and highly -resisting cord; 

extending from the ensiform cartilage of the sternum to 

the symphysis pubes. 
Linea aspera. A rough projection at the posterior surface of 

the femur, for the attachment to muscles. ' 
Ligamentum arcuatum externum. The thickened upper mar- 
gin of the anterior lamella of the transversalis fascia. The 

internum is the tendinous arch across the upper part of 

the psoas magnus muscle. 
Liver. The large gland that secretes the bile in the upper 

right side of the abdomen. 
Lingual. Pertaining to the tongue. 
Ligaments. The tough bands that bind the bones together. 



248 A COMPEND OF 

Ligamentum patellae. One of the ligaments of the knee-joint. 
Lobule — lobe. Terms applied to the round projecting portions 

of organs, as the liver, lungs, and brain. 
Lobes of the brain. The principal of these are the anterior, 

middle, and posterior lobes. 
Longitudinal. Lengthwise. 

Longitudinal fissure. The division between the two hemi- 
spheres of the brain. 
Longus. Long. 

Longus colli muscle. A long muscle on the back of the neck. 
Lumbricales. Four small muscles in the palm of the hand. 
Lymphatic system. The combination of vessels and glands 

by which lymph is secreted and passed into the blood. 
Lunulse. Two thin semilunar surfaces on either side of the 

corpus arantii of the semilunar valves of the heart. 
Long saphenous vein. The long superficial vein that passes 

from the foot up the inner side of the leg and connects 

with the femoral vein near Poupart's ligament. 
Lumbar. Pertaining to the region between the ribs and the 

pelvis. 
Malar. A bone of the cheek. 
Manubrium. The upper division of the sternum ; a name 

having other applications. 
Masseter. A muscle at the back part of the neck and lying 

upon the ramus of the lower jaw bone. 
Mastoid process. The petrous portion of the temporal bone 

behind the ear for the attachment of the sterno-mastoid, 

splenius capitis, and tracheo-mastoid muscles. 
Malleolus. The two projections formed by the bones of the 

leg at their lower part. The inner belongs to the tibia, the 

outer to the fibula. 
Mammary. Relating to or connected with the glands and 

muscles of the breast. 
Malleus. The longest and outermost of the four small bones 

of the ear. 



ANATOMY AND TIIYSIOLOGY. 249 

Materia Medica. The substance or material of medicine. 

Magnum. Great. 

Medulla oblongata. The expansion of the spinal cord within 
the skull. 

Medullary. Belonging to or of the nature of medulla or 
marrow. 

Metacarpal. Pertaining to the metacarpus or the five bones 
attached to the wrist. 

Metatarsal. Pertaining to that portion of the foot embracing 
the five long bones attached to the tarsus or ankle. 

Meatus. An orifice or small opening. 

Median line. A middle line. 

Meningeal. Relating to the dura mater. 

Mediastinum. The region in the thorax between the two 
pleurae inclosing the heart and pericardium. 

Mesentery. The portion of the peritoneal sac that invests the 
small intestine. 

Membranes. Different thin organs, representing more or less 
elastic webs, varying in then* structure and vital proper- 
ties and intended for the absorption and secretion of 
certain fluids, and to separate, envelop, and form other 
organs. 

Meta. Together with. A common prefix to terms. 

Mitral valve. This valve guards the auriculo-ventricular 
orifice of the left side of the heart. 

Minimi. The least portion. 

Motor oculi. A motor muscle of the eyeball (oculo-motorius). 

Muscles. The fleshy, fibrous bands by which all the motions 
of the organs of the body are effected. 

Mucous membrane. So called on account of the mucous fluid 
by which it is constantly lubricated. Mucous membranes 
line the canals, cavities, and hollow organs which com- 
municate externally by different apertures on the skin. 

Myology. The science which treats of the muscles. 

Nasal. Relating to or belonging to the nose. 



250 A COMPEND OF 

Nares. The four apertures — anterior and posterior — connect- 
ing the nasal fossae with the pharynx and with the front 
of the face. 

Nervous plexus. The network of nervous fibres by which 
different nerves unite and inosculate, to again separate 
and send branches to different parts. 

Neurology. The science which treats of the brain and nervous 
system. 

Obturator. A name given to certain muscles, blood-vessels, 
and nerves connected with and passing through the fora- 
men in the ischium, which is also called the obturator 
foramen. 

Occiput. The prominence on the back part of the skull. 

Occipito-frontalis. The thin muscle covering the entire front, 
top, and back part of the head. 

Occipital. Relating to the occipnt. 

Oculo-motorius (motor oculi). The muscle that moves the 
eyeball. 

(Esophagus. The passage from the pharynx to the stomach. 

Olecranon. A large process at the head of the ulna. 

Olfactory bulb. The root of the nerves of the sense of smell, 
on the base of the anterior lobe of the cerebrum. 

Ophthalmic. That which relates or belongs to the eye. 

Optic. That which relates to vision. 

Opponens pollicis and Opponens minimi digiti. Two muscles 
of the hand. 

Orbicularis palpebrarum, A muscle surrounding the orbit of 
the eye, whose function is to close the eye. 

Orbicularis oris. The sphincter muscle around the mouth 
whose function is to bring the lips together. 

Oshyoides. The bony arch that supports and gives attach- 
ment to the tongue. 

Osseous. Of the nature of bone. 

Osteology. The science that treats of the bones. 

Os calcis (calcaneum). The strong bone that forms the heel 
of the foot, to which the tendo Achillis is attached. 



ANATOMY AND PHYSIOLOGY. 25 I 

Osseo-fibrous canals. Bony and fibrous channels for the 
diffusion of blood in the substance of bone. 

Palate. The roof of the mouth and its attachments at the 
back part of the cavity, to which the uvula also is attached 
at the entrance to the pharynx. 

Patella. The small sesamoid bone covering the front of the 
knee-joint. 

Palmaris— magnus, longus, brevis. Three muscles in the 
palm of the hand. 

Papillary. Pertaining to the nipple. 

Papillse. Eminences more or less prominent at the surface of 
several parts, particularly of the skin and mucous mem- 
branes. In some situations they are also called villi. 

Pancreas. The gland behind the stomach, extending from the 
spleen to the duodenum, which secretes and discharges 
the pancreatic juice into the duodenum. 

Parietes — parietal. A name given to parts that form the in- 
closures or limits of different cavities of the body, as the 
parietes of the chest, cranium, and abdomen. 

Palpebral. That which pertains to the eyelids. 

Pathology. The physiology of disease. 

Parotid gland. The largest of the salivary glands, situated 
in front of the ear. 

Palpebrae. The eyelids. 

Periosteum. The membrane that covers the bones. 

Perichondrium. The investing membrane of cartilages. 

Pericranium. The periosteum of the skull. 

Pelvis. The bony framework attached to the lower portion 
of the spinal column, composed of the sacrum and ossa in- 
nominata, to which the two femurs are attached. 

Pectoralis major. A large flat triangular muscle situated in 
the upper part of the chest in front of the axilla. Pecto- 
ralis minor is beneath it. 

Peroneous — longus, tertius, and brevis. Three muscles on the 
anterior aspect of the leg below the knee. 

Peroneal, Belonging or relating to the fibula. 



252 A COMPEND OF 

Pectineus. A muscle on the upper and inner part of the thigh. 

Peristaltic. Of the nature of certain peculiar involuntary un- 
dulations or motions of parts, especially of the intestines, 
which sometimes continue after death. 

Peritonitis. Inflammation of the peritoneum. 

Petrous. Resembling stone. 

Pericardiac. Relating to or connected with the pericardium. 

Perineal. Relating to or belonging to the perineum in the 
lower portion of the body. 

Pedis. Of the foot. 

Pepsin. A substance produced from the stomachs of certain 
animals and introduced into the human stomach to pro* 
mote healthy digestion. 

Phalanx (plural, phalanges). The long bones of the hand con- 
necting the wrist with the fingers and of the foot* connect- 
ing the ankle with the toes. 

Pharynx. The cavity at the back of the mouth opening into 
the oesophagus. 

Phrenic. Pertaining to or connected with the diaphragm. 

Pisiform. Pea-like — pea-shaped. 

Pinna» Pavilion of the ear. 

Pia mater. The membrane investing the brain within the 
dura mater. 

Platysma myoides. A muscle situate superficially on the lat- 
eral parts of the neck. 

Plantaris — plantar. Relating to the sole of the foot. 

Plaits or rugae. Terms applied to the wrinkled formations in 
the lining membrane of the stomach. 

Pleurae. The two membranous sacs investing the lungs. 

Plexiform. Having the form of a plexus. 

Pneumogastric. From the Greek pneuma, spirit or wind, and 
gaster, stomach. The nerve that originates in the medulla 
oblongata and passes down to distribute its filaments to 
the heart, lungs, and stomach, and other internal viscera, 

Posterior, The back part, 



ANATOMY AND PHYSIOLOGY. 253 

Poupart's ligament. A broad band of aponeurosis extending 
from the anterior superior spine of the ilium to the spine 
of the os pubis. 

Popliteal space. The space extending from the aperture in the 
adductor magnus to the lower border of the popliteus 
muscle. It occupies the lower third of the thigh and the 
upper fifth of the leg, on the posterior side. 

Pons Varolii. The central portion of the base of the brain, 
forming the connection between the cerebrum and the 
medulla oblongata. 

Portal vein and its branches. The vascular system that carries 
the blood from the stomach, spleen, pancreas, and intes- 
tines to the liver, to be there acted upon previous to its dis- 
charge through the hepatic veins into the vena cava to be 
• conveyed to the heart. 

Profunda femoris arteria. The largest branch of the femoral 
artery in the thigh. 

Prognosis. Foreknowledge of disease from present symptoms. 

Pubes. The anterior portion of the pelvis. 

Pulmonary. Relating to the lungs. 

Pylorus. The passage from the stomach to the duodenum. 

Quadriceps extensor, Rectus femoris, Vastus externus, Vastus 
internus, and Crureus. Muscles of the thigh. 

Radius. The larger and stronger of the two bones of the 
forearm. 

Ramus of the jaw. A portion that forms an angle with the 
body or main portion. 

Ranine. A branch of the lingual artery ; it is accompanied 
by a vein of the same name that opens into the internal 
jugular or thyroid vein. 

Raphe. A name given to prominent lines resembling a raised 
stitch, dividing certain organs of the body rig] it and left. 

Rete mucosum (corpus mucosum). The second layer of the 
skin, situate between the cutis vera and cuticle, which 
gives the color to the body. 



254 A COMPEND OF 

Renal. Related to or belonging to the kidney. 

Retina. The inner surface of the back part of the eyeball 
upon which the images are formed in the act of vision. 

Recurrent. A name given to certain vascular and nervous 
branches that seem to return to the trunks from which 
they emanated. 

Regurgitation. The act by which a canal or reservoir throws 
back substances accumulated in it. 

Rotula. Another name for the patella or the sesamoid bone, 
sometimes called the knee-pan. 

Rolando. One of the prominent fissures formed by convolu- 
tions in the upper portion of the brain. 

Sacrum. The lower section of the spinal column, forming the 
back part of the pelvis. 

Sagittal (arrow-shaped). The name of one of the sutures of 
the cranium. 

Sartorius. A long narrow muscle extending from the an- 
terior superior spinous process of the ilium obliquely 
downward across the front of the thigh, to be inserted into 
the upper part of the inner surface of the shaft of the 
tibia. 

Sacro-sciatic foramen. The large opening in the lower portion 
of the pelvis, through which pass the great sciatic nerves. 

Saphenous. A name given to several veins and nerves in the 
lower extremity. 

Scarpa's triangle. The space on the front of the thigh in- 
cluded between Poupart's ligament above and the sar- 
torius and adductor longus muscles below. 

Scapula. The flat bone, commonly called the shoulder-blade, 
which unites with the clavicle in articulation with the 
humerus to form the shoulder- joint. 

Sclerotic. The external coating of the eyeball, the front part 
of which is the white of the eye. 

Segments. The divided parts of the whole. 

Serratus magnus. A very broad, thin, flat muscle situate at 



ANATOMY AND PHYSIOLOGY. 255 

the side of the thorax and attached to the upper ribs and 
the scapula. 

Seini-membranosus. A muscle on the posterior part of the 
thigh. 

Semi-tendinosus. Also a muscle on the posterior part of the 
thigh. 

Sensitive papillae. Such as are capable of sensation, as those 
on the dorsum of the tongue. 

Sebaceous glands. Small hollow organs of a rounded or pyri- 
form shape in the substance of the skin and opening on 
its surface by small excretory ducts ; furnishing a yellow 
unctuous humor. 

Septum. A part designed to separate two cavities or portions 
from each other. 

Serous membranes. Those that secrete the most watery por- 
tion of animal fluids. 

Secretion. An organic function, chiefly executed in the 
glands, and consists in an elaboration or separation of the 
materials of the blood, at the very extremities of the 
arterial system, and which differs in each organ according 
to its particular structure and function. 

Sesamoid bones. Small bones situate in the substance of 
tendons, near certain joints. 

Semilunar. The name given to certain valves and glands that 
somewhat resemble a half moon in form. 

Secundi. Second. 

Sinistra. The left side. 

Sigmoid. That which has the form of the Greek letter sigma, 
as the sigmoid flexure of the descending colon. 

Sinus. Any cavity in which the interior is more expanded 
than the entrance. This is especially the case with certain 
cavities in the cranium, spine, and heart. 

Soleus. A broad flat muscle, situate beneath the gastrocne- 
mius on the upper back part of the leg. 

Soft palate. The posterior extension of the hard palate at the 
entrance to the pharynx. 



2$6 A COMPEND OF 

Spinal column. The succession of vertebrae .through which 

passes the spinal cord, extending f roih the base of the skull 

to the lower extremity of the trunk. 
Spinal accessory nerve. A nerve originating* in the medulla 

oblongata, having two distinct divisions, one of which 

unites with the pneumogastric and hence becomes acces- 
sory, and the other descends to be distributed to various 

muscles in the neck. 
Spinous processes. The prominent places on the vertebrae for 

the attachment of muscles. 
Spine of os pubis. The prominence on the anterior portion of 

the pelvis. 
Splenius. A muscle situate at the back of the neck. 
Splenic. Pertaining to or belonging to the spleen. 
Sutures. The irregular jagged joints connecting the bones of 

the skull. 
Squamous. Scale-like in form. 
Sternum. The breast-bone to which the cartilages of the ribs 

are attached. 
Styloid process. A name given to certain prominences on the 

fibula, radius, and ulna, and other bones. 
Sterno-cleido-mastoid. The muscle attached to the upper part 

of the sternum and the mastoid process at the base of the 

skull behind the ear. 
Strata. Formations by parallel layers. 
Stapes. One of the small bones of the ear, so called from its 

resemblance to a stirrup. 
Supinator longus. The most superficial muscle on the radial 

side of the forearm. 
Sudoriferous or sweat glands. The organs by which a large 

portion of the aqueous and gaseous materials are excreted 

by the skin. 
Subcutaneous. Under the skin. 
Sublingual. Beneath the tongue. 
Submaxillary. Pertaining to the lower jaw. 



ANATOMY AND PHYSIOLOGY. 257 

Sulci. The divisions of the convolutions of the brain. 

Submental. The large branch of the facial artery sending; its 
branches to the muscles of the lower jaw. 

Supra-orbital. Above the orbit. 

Subclavian. Beneath the clavicle. 

Superior. Upper, above, or at the top. 

Subscapular. Beneath the scapula. 

Suprarenal. Above the kidney. 

Syndesmology. The science which treats of the ligaments. 

Synovia. The lubricating fluid of the joints. 

Sweat-glands. See Sudoriferous. 

Sylvius. The fissure between the anterior and middle lobes 
of the brain. 

Symphysis pubis. The central portion of the front of the 
pelvis, where the two ossa innominata are united. 

Sympathetic nerves. The great nerves within the body ex- 
tending from the brain along the sides of the spine to its 
lower extremity, on which are numerous ganglia for the 
reception and distribution of branches to the viscera 
within the body. 

Tarsus. The combination of bones forming the ankle-joint. 

Temporal. The name of the bones at the sides and base of 
the skull. 

Tendons. The strong fibrous cords by which certain muscles 
are attached to the bones. 

Tendinous. Having the qualities of tendons. 

Tendo Achillis. The strong tendon on the back of the leg 
connecting the muscles with the os calcis. 

Tentorium cerebelli. An arched lamina of dura mater that 
covers the upper surface of the cerebellum. 

Therapeutic. Pertaining to curative processes. 

Thorax. The cavity formed by the spine, the ribs, and the 
diaphragm, inclosing the heart, lungs, and their accesso- 
ries. 

Thoracic duct. The vessel that conducts the nutritious ele- 
*7 



258 A COMMEND Of 

merits of the food from the small intestines up along the 

spine, and discharges its contents into the left subclavian 

vein. 
Thymus. A temporary gland situate in the upper part of the 

anterior mediastinum, which almost or entirely disappears 

in the adult. Its function is unknown. 
Thyroid. A gland situate at the upper part of the trachea, 

consisting of two lateral lobes on the sides of that tube. 

Its function is not known. 
Tibia. The larger of the two bones of the leg below the knee, 

situated on the inner side. 
Tibialis posticus. A muscle on the back of the leg. 
Tonsils. Two glandular organs, one on each side of the fauces 

between the anterior and posterior pillars of the soft 

palate. 
Tissue. A term applied to various kinds of structures in the 

body, as fibrous tissue, glandular tissue, etc. 
Tortuous. Undulating in its course. 
Trunk. The body from the neck to the lower portion of the 

pelvis. 
Trochlea. A portion of the articular surface of the lower ex- 
tremity of the humerus. 
Trochanter (greater and lesser). Two processes on the internal 

and external portion of the upper extremity of the femur. 
Trapezius. A large thin triangular muscle on the back of the 

neck and shoulder. 
Triceps. The great extensor muscle of the forearm, extending 

the entire length of the humerus on its posterior side. 

This term is also applied to a threefold muscle on the front 

of the thigh. 
Transversalis. The most internal flat muscle of the abdomen. 
Transverse. Crosswise. 
Trachea. The windpipe. 
Tricuspid valve. One of the valves of the heart, consisting 

of three segments. 



ANATOMY AND PHYSIOLOGY. 259 

Tuberosities. Prominent places at the extremities of certain 

bones for the attachment of muscles. 
Tubercle. A term given to certain osseous formations and also 

to certain constitutional formations in the internal viscera. 
Turbinated. A name given to certain bones in the face. 
Tunic. A certain peculiar fibro-tendinous attachment of 

organs. 
Tuber cinereum. An eminence of gray matter in the base of 

the brain between the optic tract and the corpora albi- 

cantia. 
Tympanum. The middle ear ; an irregular cavity, compressed 

from without inward and situated within the petrous 

bone. 
Ulna. The long bone on the inner side of the forearm. 
Uvula. A small conical-shaped pendulous process hanging 

from the middle of the lower border of the soft palate in 

the back of the mouth. 
Vascular. Relating to the blood. 
Vasomotor nerves. Nerves controlling the arteries. 
Vertebrae. The bones of which the spinal column is composed. 
Vertebral arteries. Two branches of the subclavian arteries 

that pass up the neck and distribute their branches to the 

back part of the base of the brain. 
Vena cava (superior or descending and inferior or ascending). 

The two large veins in the thorax and abdomen that 

receive the blood from the entire body and pass it into the 

right auricle of the heart. 
Vena azygos. The veins that connect the inferior and superior 

vena cava, and from which issue the intercostal veins. 
Vena innominata. The large veins in the upper part of the 

thorax, which unite to form the superior vena cava. 
Venter ilii. The large, smooth concave anterior surface of the 

ilium. 
Ventricles. Certain cavities in the heart and brain. 
Vesicle. A little bladder-like formation. 



26o A COMPEND OF ANATOMY AND PHYSIOLOGY. 

Vestibule. The first opening to certain organs. 

Vital organs. Organs the performance of whose functions is 
indispensable to human life. 

Viscera. Commonly signifies the organs within the body. 

Villus — villi. The minute prominences on the inner side of 
the small intestine for the absorption of nutriment from 
the chyle to be passed into certain glands and thence into 
the thoracic duct. 

Vitreous table. The inner plate of the skull. 

Vitreous humor. The jelly-like, transparent substance that 
fills the cavity of the retina, inclosed in the hyaloid mem- 
brane. 

Vomer. The thin bone forming the septum of the nose. 

Zygoma. The long narrow process attached to the temporal 
bone at the side of the face. 



CONTENTS. 



Page 

Title-page and Copyright, i, ii 

Introduction, 3-5 

INDEX TO CHARTS OF MANIKIN. 

External muscles of face and neck. Anterior view of 
muscles of right side of body. Anterior view of mus- 
cles of right arm with superficial veins. Anterior 
view of muscles of right hand, 7 

Anterior view of muscles and superficial veins of right leg 
and foot. Anterior view of deep muscles of left side 
of body. Muscles of the left arm. Deep muscles of 
left leg and foot. Muscles and tendons of left hand, 8 

Anterior view of blood-vessels of face and neck. Thorax, 
showing lungs and heart between the ribs. Blood- 
vessels of left side of face and anterior section of heart 
and lungs. Anterior view of stomach and intestines, 
the omentum having been removed, .... 9 

Anterior and posterior views of stomach and liver. Lat- 
eral view of section through middle of skull, face, and 
neck, showing internal structure. Deep viscera of 
thorax and abdomen, 10 

Arteries of right arm with their venaB comites. Arteries 
and deep veins of right hand. Arteries and deep 
veins of right leg and foot, , , . , . , 11 



262 CONTENTS. 

PAGE 

Principal nerves and blood-vessels of left arm. Principal 
veins of left hand. Anterior view of nerves of left 
leg and foot, Inebriate's brain with enlarged blood- 
vessels. Alimentary canal with organs separated. 
Diagram of circulation of blood, 12 

Confirmed inebriate's ulcerated stomach. Condition of 
stomach after death by delirium tremens. Illustra- 
tion of capillary circulation. Blood-corpuscles. Villi 
of intestines. Salivary glands. Vertical section of 
heart, showing ventricles. Lateral section through 
face and throat. Under side of liver. Posterior view 
of small intestines. External posterior muscles of leg, 13 

Posterior view of leg with external muscles removed. - 
Lateral view of skull and anterior view of cervical 
vertebra and thorax. Lateral view of convolutions 
of brain and cavity of mouth. Base of brain with 
roots of cranial nerves and arteries, .... 14 

Lateral section through middle of brain with cranial 
nerves. Anterior view of spinal column with spinal 
nerves and lymphatics. The pelvis. Bones and 
lymphatics of right arm. Bones of right hand. Bones 
and lymphatics of right leg and foot, ... .15 

Bones and nerves of left arm. Bones and nerves of left 
hand. Bones and nerves of left leg and foot. Pos- 
terior view of skull, spinal column, and ribs. Great 
sympathetic nerve, 16 

Small section of spinal corcj. Section of inferior maxil- 
lary bone of an infant. Valves of a vein. Arch of 
aorta ruptured. The caecum laid open. Section of 
small intestine laid open. Posterior view of left leg. 
Section of head of femur, showing texture of bone. 
Ligaments of elbow, wrist, shoulder, hip, ankle, and 
knee. Lateral view of section of the middle of foot, . 17 



CONTENTS. 263 

PAftE 

Vertical section of bone, showing texture and arteries 
Anterior view of glands and ducts of the eye. An- 
terior view of eyeball. Eyeball as seen from above 
Transverse vertical section through middle of eye 
External ear. Bony labyrinth of ear, . . . . 18 

External and internal ear. Tongue and throat. Epithe- 
lial cancer. Tongue and tonsils. A molar tooth. Sec- 
tion of molar tooth. Section of bicuspid tooth. Sec- 
tion of skin. Larynx, . 19 

Lateral view of larynx. Anterior view of stomach. In- 
ternal view of stomach. Transverse section of thorax. 
Anterior view of heart. Section of heart — parts sep- 
arated, 20 

Transverse horizontal section of heart. Muscles and ten- 
dons of foot. External kidney. Internal kidney. 
Fatty degeneration of kidneys. Muscles and tendons 
of sole of foot. Muscles and tendons of inside of foot. 
Arteries and tendons of back of hand, ... 21 

Muscles and ligaments of wrist and hand. Arteries of 

hand, 22 

HUMAN ANATOMY AND PHYSIOLOGY. 

Divisions of anatomy, 23 

Explanation of the reference numerals, .... 24 

BONES. 

General description, 24 

Bones of the Cranium, Face, Spinal column, ... 25 
Bones of the Pelvis, Ribs, Tongue, Sternum. Bones of 
the Shoulder, Arm, Wrist, Hand. Bones of the Fin- 
gers, Legs, Ankle, Foot. Bones of the Toes, Teeth, 
Sesamoid, 2G 



264 CONTENTS. 



PAGE 



Different kinds of bones, 27 

The skull and its parts, 28 

The spinal column and its parts, 29 

Cervical, Dorsal, Lumbar, and Sacral vertebrae, . . 30 

The Pelvis, Thorax, 31 

The Clavicle and Scapula, . 32 

The Humerus, Radius, and Ulna of the Arm, ... 33 
The Carpus, Metacarpus, and Phalanges of the wrist and 

hand. Bones of leg, Femur, 34 

Hip and Knee joints, 35 

Tibia and Fibula, .36 

Bones of the ankle and foot, Tarsus, os calcis, ... 36 

Metatarsus, 37 

LIGAMENTS. 

General description, . . 38 

Local ligaments, 38 

Ligaments of wrist and ankle and Poupart's, . . . 39 

MUSCLES, TENDONS, FASCIiE, APONEUROSIS. 

General description, 39 

Detailed description, 40 

Muscles of the head, face, and neck, 41 

Anterior muscles on the right side of body, . . . 42-43 

Anterior muscles of the right arm, 44 

Muscles of the hand, 45-46 

Muscles of the leg. Anterior muscles of thigh, . . 47 

Tibialis Anticus, 48 

Adductor longus. Adductor magnus. Vastus externus, 49 

Peroneus longus, brevis, Gluteus maximus, ... 50 

Semi-tendinosus, Gluteus minimus, 51 

Semi-membranosus 52 

Biceps, Gastrocnemius, 53 

Soleus, ', 54 



CONTENTS. 265 

PAGE 

Plantaris, Tendo Achillis 55 

Muscles and tendons of the foot. Anterior annular liga- 
ment, Internal annular ligament, External annular 
ligament, Abductor digiti minimi, Extensor digi- 

torum communis brevis, 56-57 

Internal malleolus, Adductor pollicis pedis, Os Calcis, 

Fascia Plantaris, 58 

Abductor pollicis, Abductor minimi digiti, Flexor brevis 

digitorum, 59 

THE SKIN AND ITS APPENDAGES. 

General description, 60 

Derma or true skin, corium, areolae, papillary layer, . 61 

Epidermis, arteries of the skin, lymphatics, ... 62 

Appendages of the skin, 63 

ALIMENTARY CANAL, 

The nutrition of the body, ' 63 

The salivary glands and their function, .... 64 

The Mouth. Hard and soft palate, tonsils, and pharynx, 65 

(Esophagus and Diaphragm, QQ 

Functions of the Diaphragm, 67 

Function of the tongue and saliva in digestion. Struc- 
ture of the alimentary canal, 68 

The abdomen, general description, the stomach, . . 69 
Structure and functions of the stomach, the gastric juice, 

proper diet, 70 

Process of digestion in the stomach. Pancreas, . . 71 

The Liver — its structure and functions, .... 72 
The Duodenum. Qualities of the bile and pancreatic 

juice, 73 

Digestive processes in the small intestine, .... 74 

The absorption of the digestive fluids, 7o 



266 CONTENTS. 

PAGE 

The lymphatic glands and their function in digestion, . 76 

The function of the Colon or large intestine, ... 77 

The Peritoneum. Hernia or Rupture, .... 78 

RESPIRATION. 

Its function, larynx, glottis, Pharynx, trachea, bronchi, . 79 
The structure of the bronchi and capillary system in the 

lungs, 80 

The thorax— its structure, 81 

Organs of respiration and their functions, .... 82 
Cartilages, Thyroid, Cricoid, Arytenoid, Cuneiform, Epi- 
glottis, 83 

Ligaments of larynx, thyro-hyoid membrane, ... 84 

Interior of the larynx, 85 

The glottis, 86 

Vocal cords, 87 

Ventricle of the larynx, 88 

Muscles of the larynx, 89 

Vessels and nerves of larynx, 90 

THE TRACHEA. 

The structure and relations of the windpipe, ... 91 

Right and left bronchus, 92 

The pleura and mediastinum, 93 

Relations of the pleura, 94 

Vessels and nerves of the pleura. The lungs, ... 95 

Lobes and fissures of the lungs, 96 

Substance of the lungs, 97 

Distribution of the bronchial tubes in the lungs, . . 98 

Pulmonary arteries and capillaries, 99 

Bronchial arteries, Bronchial veins, Lymphatics, Nerves, 100 

Thyroid gland, Thymus gland, 101 

Movements of respiration, ,,,,,,, 102 



CONTENTS. 267 

PAGE 

Movements of inspiration and expiration, .... 103 

Movements of the glottis, 104 

Changes in air by respiration, 105 

Oxygen, nitrogen, carbonic acid, 106 

The constituents of air before and after its passage 

through the lungs, 107 

Respiration exhausts the substance of the body, . . 108 

Changes of the blood in respiration, 109 

Red and white globules in the blood, 110 

Exhalation of carbonic acid by the blood, .... Ill 

Oxygen and carbonic acid, 112 

ORGANS OF THE CIRCULATION OF THE BLOOD. 

General description of the circulatory system, . . . 113 

Structure of the heart, 114 

Auricles and Ventricles, 115 

Passage of blood through the heart, 116 

Size of heart and its position, .117 

The pericardium and its relations, 118 

Arterial circulation, 119 

Arterial pulse, 120 

Variations of the pulse, 121 

The arteries, 122 

Anastomosis and distribution of arteries, .... 123 

The aorta, 124 

Carotid arteries and branches, 125 

Branches of external carotid, 126 

Internal carotid artery and branches, . . . .127 

Subclavian arteries. Vertebral arteries, .... 128 

Inferior cerebellar artery. Basilar artery, . . . 129 
Cerebral branches of internal carotid, . . . .130 

Circle of Willis, 131 

Internal mammary artery, 132 

Superior intercostal artery, 133 



263 



CONTENTS. 



PAGE 

The axilla and its artery and branches, . . . . 134 

Radial and Ulnar arteries, 135 

Descending aorta, . . 136 

Abdominal aorta, 137 

Superior mesenteric artery, 138 

Inferior mesenteric artery. Renal arteries, . . .139 

Phrenic arteries. Lumbar arteries, 140 

Common iliac arteries, 141 

Internal iliac arteries, 142 

External iliac artery, 143 

Femoral arteries, 144 

Profunda femoris, 145 

Popliteal. Anterior tibial artery, 146 

Dorsalis pedis. Posterior tibial, 147 

Peroneal, Anterior peroneal. Internal plantar arteries, 148 



VEINS. 

General description. Pulmonary, Systemic, and portal 
veins, 

Valves of the veins, 

Superficial and deep veins and sinuses, 

Veins of the head and neck. External Jugular, 

Internal jugular and Anterior jugular, 

Veins of the arm and hand, 

Anterior Ulnar, Posterior Ulnar, Basilic, Radial, 
phalic, 

Median, Median Cephalic, Median Basilic veins, 

Deep veins of the forearm and Axillary, . 

Subclavian Veins and Venae Innominate, . 

Superior Vena Cava, Azygos Veins, . 

Left azygos veins, 

Spinal veins and veins of lower extremity, 

Internal and external saphenous veins, 

Deep veins of the leg, ,,,... 



Ce 



149 
150 
151 
152 
153 
154 

155 

156 
157 
158 
159 
160 
161 
162 
163 



CONTENTS. 269 



PAGE 

Femoral, external and internal iliac veins, . . . 164 
Common iliac veins. Inferior Vena cava, . 
General description of Portal system, 
Renal veins. The kidneys, .... 
Suprarenal Capsules, 



165 
166 
167 
168 



CONSTITUENCY OF THE BLOOD. 



Plasma and globules, 169 

Ingredients of Plasma, 170 

CAPILLARY CIRCULATION. 

General description, .171 

Condition of blood in the capillaries, . . . . . 172 

NERVOUS SYSTEM. 

General description. The Brain, 173 

Cerebrum — upper surface. Convolutions, . . .174 

Variety of Convolutions, 175 

Cerebrum — under surface, . . . . . . .176 

The hemispheres, Cerebellum, Pons Varolii, and Medulla 

oblongata, 177 

Size and weight of brain. Dura mater, . . . . 178 
Arachnoid membrane. Pia mater. Spinal cord, . . 179 

The Ganglia, 180 

Spinal Nerves, 181 

Cervical nerves and plexus, 182 

Branches of cervical nerves, 183 

Phrenic nerves and other branches of cervical plexus, . 184 

Brachial plexus, .185 

Location and structure of brachial plexus, . . .186 
Branches of brachial plexus above the clavicle, . . 187 
Branches of brachial plexus below the clavicle, . . 188 



27(3 CONTENTS. 

PAGE 

Median and Ulnar nerves, 189 

Musculo-spiral Nerve, 190 

Dorsal Nerves, .' 191 

Intercostal Nerves, 192 

Lumbar Nerves, . . 193 

Lumbar Plexus, 194 

Branches of Lumbar Plexus, 195 

Anterior nerves of thigh, 196 

Crural Nerve, 197 

Sacral and Coccygeal Nerves, 198 

Anterior Sacral Nerves, 199 

Sacral Plexus, 200 

Posterior Nerves of Thigh, 201 

Great Sciatic Nerve. Internal Popliteal, .... 202 

Posterior Tibial Nerve, . .203 

Peroneal and Anterior Tibial nerves, 204 

Branches to the Tarsus, . 205 

The Sympathetic Nerve, 206 

Ganglia of the Sympathetic, 207-210 

Cardiac Nerves, 211 

Splanchnic Nerves, 212 

Solar Plexus. Semilunar Ganglia, 213 

Gastric Plexus. Lumbar Sympathetic, .... 214 

Organs of Sense. The Tongue, 215-216 

The Nose, . . . 217-218 

Nasal Fossae, . . . .219 

The Eye, 220-224 

Appendages of the Eye, . . . . . 225-226 

Lachrymal Apparatus, . . . . . . . . 227 

Sense of Hearing, 228 

External Ear, 229 

Malleus, Incus, Stapes, Tympanum, Eustachian tube, . 230 

Labyrinth, Cochlea, 231 

Distribution of auditory nerve, 232 



CONTENTS. 271 

PAGE 

Physiology of Labyrinth, 233 

Organ of Corti, 234 

Physiology of the Cochlea, 235-236 

Glossary, 237-260 

Contents, 261-271 



